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FAQs on Oscar Compatibility 

Related Articles: Oscars, Neotropical Cichlids, African Cichlids, Dwarf South American Cichlids, Cichlid Fishes in General

Related FAQs: Oscars 1, Oscars 2, Oscar Identification, Oscar Selection, Oscar Behavior, Oscar Systems, Oscar Feeding, Oscar Disease/Health, Oscar Reproduction, Neotropical Cichlids 1, Cichlids of the World, Cichlid Systems, Cichlid Identification, Cichlid Behavior, Cichlid Compatibility, Cichlid Selection, Cichlid Feeding, Cichlid DiseaseCichlid Reproduction,

My Oscar swallowed my silver dollar!       10/24/15
Hello.
I'm a bit concerned for my Oscar. He/she (I don't know) has swallowed my last silver dollar. My Oscar is about 5 inches long and the silver dollar is almost 1 inch,
<Ah yes; a foregone conclusion that this would happen
>
he seems to be gulping but the fish doesn't seem to be moving down his throat. He's pooping quite a bit, and still slowly swimming around the tank. I'm just scared to go to bed and find that he's choked by the time I wake up. Please help me!
Hannah
<Well; even if the dollar was "swallowed backward" (the fin spines slowing the rate of ingestion); eventually the fish will make its way down the Oscar's gullet. I would leave all as it is; though IF this had just happened; there are some folks that would mention the possibility of removing the Oscar with a net, holding it in a wet towel, and trying to extract the Dollar. I would not. Likely it has perished, and the Oscar will not suffer harm. Bob Fenner>

Hello I am new to the site I have a few concerns about my tiger Oscar. I     7/25/15
bought him 2 weeks ago he/she is a juvenal
<I presume you mean a juvenile rather than he's called Juvenal after the Latin poet?>
I also got a jack Dempsey with my Oscar they were in a tank together.
<Poor choice. How big is this tank? Some hundreds of gallons?
Otherwise this won't work. Both species are territorial, and the JD is, for its size, quite a powerful fish and can/will damage a young Oscar without any
problems at all.>
When I got them home all was good, after 2 days my Oscar acted aggressive then stopped and the jack Dempsey started getting very aggressive. He would attach my Oscar when he ate or even swam near the Dempsey.
<Separate them.>
I thought maybe it would pass but after a day or so it got worse the Dempsey like stalked my Oscar would bite him.
<Separate them.>
I got ride of the Dempsey and now its just my Oscar, it is alone now but his fins have splits in them and he lays around sometimes on his side.
<Separate them.>
I got some Melafix to help him heal his fins a spot on his side.
<Melafix is not reliable or even particularly useful. You need to (a) separate them, and (b) medicate the Oscar as per Finrot. It should recover and grow its fins back if you act promptly.>
I'm worried about him he doesn't follow my hand any more like he did he hides when I try to feed him and will only come out when it is dark to swim around or eat. Is he still scared and will the treatment hurt him? I'm new at this fish stuff.
<It would seem so. To be blunt, Oscars are demanding fish for experienced, and to some extent rich, fishkeepers. They need a lot of space, at least 90 US gallons and honestly more like 150 US gallons if you don't want to be
constantly changing the water and/or dealing with health problems (Hexamita and HITH are two classic problems for the Oscar kept in a "small" tank).
JDs aren't especially difficult to keep, being relatively small, 7-8 inches maybe, but they are nasty fish for their size, and usually kept alongside other equally waspish cichlids or else alone. An Oscar is, by nature,
territorial but peaceful, and usually kept either alone or with jumbo community fish that aren't cichlids -- Plecs, Silver Dollars, Fire Eels, and so on. They aren't particularly aggressive except when breeding, and lack the psychotic streak characteristic of many Central American cichlids.
Finally, note that Oscars are soft water fish from South America, and don't want the same water chemistry as Central Americans like JDs that need hard, alkaline water chemistry. In short: separate them.>
Catherine
<Hope this clears things up for you. Cheers, Neale.>
re:      7/26/15

Thank you I did however get rid of the JD and my Oscar is doing better thanks again
Catherine
<Glad to help. Do be sure and read: http://www.wetwebmedia.com/fwsubwebindex/oscars.htm
Better to avoid rather than cure further problems with these difficult,
demanding cichlids if you can. Cheers, Neale.>

ANOTHER Oscar question      2/9/14
WWM, you guys are outstanding, and I constantly read your responses.
<Thanks for the kind words.>
I couldn't find my specific problem, so I'm writing to you, a befuddled man. I have a 110 gallon tank, 35 gallon sump, 1800gph return pump, UV sterilizer, etc etc. The tank is established (though my Ph is rather high at 8.2, but I'm not going to chase it.) I have 11 silver dollars, tons of live plants (I found a system that works. Haha) and one juvenile Oscar.
He's about 4 months old, and 5 1/2 inches long. I feed him daily, and his diet is varied. (NO FEEDERS.) Until the last week, we had no issues, but now he's attacking my silver dollars. He will literally swim up to one, and bite it in the side, sending scales flying! Is he just being a teenager?
<Probably not; he's stimulated by the sight of potential prey, and acting as nature programmed him too. If the Silver Dollars are too big to harm and the tank has enough space, you may find he eventually ignores them once he figures out they aren't easy to catch. Offering some equally stimulating alternatives might help, for example pieces of fresh seafood or even live
earthworms and/or river shrimps. But of course if the Silver Dollars are small ones, he might eventually catch and kill one of them, in which case separating them (perhaps with an egg crate divider) might be necessary until they get bigger. You might also try and see if your Oscar is being territorial (i.e., defending one end of the tank from oncoming Silver
Dollars) or predatory (i.e., just randomly sneaking up and attacking wherever in the tank he happens to be). That would give a clue to what's going on. Oscars generally aren't territorial to dissimilar non-cichlid fish given space, but if yours is, then the old "take the aggressive fish out, move all the rocks and plants about, then reintroduce the fish" trick might work. Often does, with cichlids, tricking them into thinking they're somewhere new and so resetting their territorial instincts.>
I just picked up a 65 I plan to cycle, to move him to his own space, but this really confuses me. Help me with my jerk Oscar? Thanks for all you guys do!
-Tom
<Most welcome, Neale.>
<<I'd add one more statement to Neale's excellent input here. I suspect the Oscar may be reacting to its own (internal) reflection in the side/glass. I suggest you tape a piece of paper over this to see if it has a calming effect. This sort of territorial display is quite common amongst cichlids (and many marine Teleosts). Cheers, Bob Fenner>> 

Re: ANOTHER Oscar question      2/9/14
I will try that, too. I'd like to keep him where he is, so all of this is very appreciated.
<Real good. BobF>

re: ANOTHER Oscar question... add incomp. w/ silver $      2/9/14
Neale,
Yes, he seems to stalk them and attack them once in a while, definitely not confined to any one area. I will try re arranging the tank and reintroducing him, as per your recommendation. If that fails, I'll try giving him more worms, etc. I feel bad because the older silver dollar (7 inches, eight years old) is starting to get stressed, and has a bunch of scales missing from where he pecks at her. If all else fails, I'll just put him in his own tank. Thank you so much for your quick response!
-Tom
<Most welcome and good luck. Cheers, Neale.>
RE: fw: re: ANOTHER Oscar question

Bob,
This may seem weird, but I've noticed he gets a lot more aggressive right after I feed him his worms. Within two minutes of eating a few meal worms, he's nipped four silver dollars and uprooted a plant. Don't know if that helps or not.
<Bob may/may not agree, but there's a lot of experience to suggest that using live food increases aggression and predatory behaviour, whereas the use of obviously dead food (like pellets) has the opposite effect. One of many reasons why feeder fish are a bad idea. Cheers, Neale.>
<<I very much agree. You can see my similar stmt.s in this regard in several places on WWM, in writings elsewhere. B>>
RE: fw: re: ANOTHER Oscar question      2/10/14
You guys are truly genius! The distraction method works! I put a bobber, and a de hooked spinner in the tank. (What we used to catch wild Oscar in florida) Now he likes to sneak up and ambush my lure. Thank you, from my silver dollars and myself!
-Tom
(Pic included.)
<Looks cool! Neale.>

 Re: ANOTHER Oscar question     2/10/14
I swear Bob and I are different people… not the same person with American, British accents!
Neale
<Heeeee! I think I like domestic cats more! B>

HELP, Astronotus fighting; no data, rdg.       1/13/14
My Oscars have been cohabitating for several months with a few minor little spats but nothing major.  However, recently my biggest Oscar has scales missing on both sides of his body and seems to be hiding in the corner of the tank.  I am not sure if the missing scales is a disease or something else?  Please help this Oscar has been with us for a very long time I don't want to lose him. please help me save my big dude I don't want him to die….
<Size of system? Water quality? Not uncommon behavior... read here: http://wetwebmedia.com/FWSubWebIndex/oscars.htm
and the linked files above. Bob Fenner>

help with Oscar     10/27/13
hi, i am writing to you because since i have moved my Oscar to a larger tank he has become very aggressive. I have my Oscar in a 150  gallon tank along with the tankmate i bought him with ( a black ghost knife) . i got them both when they were very small fish and they lived in a 75 gallon tank peacefully for about a year till i figured it was time to move them to a larger tank before they got very big. My Oscar is about 7-8 inches long and the knife is about 11inches. Since the tank is still in cycle, nearing the end thought this may be the reason for his sudden aggression or maybe even just his age. plz let me know if u have anytips.thank you.
<Will send along to Neale here; but I'd consider adding some fast "dither" fish... Perhaps a few tinfoil barbs or silver dollars of size... to spread out the Oscar's aggression here. Bob Fenner>
help with Oscar; Neale's separate go      10/27/13

hi, i am writing to you because since i have moved my Oscar to a larger tank he has become very aggressive. I have my Oscar in a 150  gallon tank along with the tankmate i bought him with ( a black ghost knife) . i got them both when they were very small fish and they lived in a 75 gallon tank peacefully for about a year till i figured it was time to move them to a larger tank before they got very big. My Oscar is about 7-8 inches long and the knife is about 11inches. Since the tank is still in cycle, nearing the end thought this may be the reason for his sudden aggression or maybe even just his age. plz let me know if u have anytips.thank you.
<Your Oscar has become sexually mature, and the change in aquarium likely made him feel unsettled. In the smaller tank he'd gotten use to the Knifefish from an early age, and there's a scientific theory that suggest that animals are less aggressive to "rivals" they recognise than ones that are new. Once you moved the Oscar, the Knifefish wasn't part of the scenery any more but a new Knifefish in his territory. Yes, it's the same Knifefish, but animals don't recognise individuals, they recognise threats.
New tank, new territory, so as far as the Oscar is concerned, new Knifefish. Given time things should settle down if the fish were okay before, but do remember that Oscars and Black Ghosts have much different temperaments and to some degree requirements (the Knifefish preferring cooler water and definitely needing more current and oxygen) so you might consider keeping them in separate tanks, and building communities around their specific needs. Oscars work well with L-number catfish for example, so something like a Royal Plec would work great, and the bigger Spiny Eels can work well too. On the other hand Black Ghosts suit tanks built around fast water currents, so things like Giant Danios, medium-sized barbs, and large characins such as Silver Dollars and Anostomus could all make sense.
Cheers, Neale.>

2 Oscars changed behavior    9/12/13
Hello.. . I've Have had these same 2 Oscars together for approximately 2 maybe 3 months they are about 5 inches long they immediately hit it off and became buddies swimming side by side hanging out constantly together...
<Mmmm; won't likely go on...>
Recently when I shut the light off at night time and wake up in the morning one of them looks like he's been beat on minor bangs and scrapes not anything serious but I'm just wondering why this behavior is going on and should I be worried about it?
<Yes you should be concerned... One is beating up the other. They should be separated; and may well need to be kept so, unless they can be kept in a very large volume (hundreds of gallons), and/or mated/paired>
 It has going on  for the last week. I've noticed it because I heard them splashing around and happened to notice or
biting at the other it but as soon as the lights turn back on within a couple of minutes they're back to being buddies....help I don't want to continue torturing one of my fish if that's what's going on...I will say that the fish being bitten on is passive and doesn't fight back so I'm wondering if this may be a sign of spawning or what it could be. ... Thank you for your time
<Have you read on WWM re Astronotus? Here:
http://www.wetwebmedia.com/FWSubWebIndex/oscars.htm
and the linked files above. Bob Fenner>
Re: 2 Oscars changed behavior     9/12/13

Thank you for the information provided. . Why is this only mean behavior only occurring in the dark?
<Happens at times>
 How do I know that they are not in fact a pair?
<... too small for one. Keep reading. BobF>

Astronotus; health 12/22/11
Hi, I have two Oscars and my smaller 3 inch Oscar is turning pale. They are both black, but the smaller one is turning a pale olive green at the top of his/her body... Is this normal, what can I do, I'm extremely worried about my fishes life!
<Need some information here, Nicky. How big is the aquarium? Have you measured water quality recently? Let's recap. Oscars need big tanks and extremely heavy-duty filtration. For two specimens you'd need at least 75 gallons, even for babies, and the filter should provide a turnover rate of at least 8 and preferably 10 times the volume of the tank per hour. For two Oscars, I'd be using two Eheim 2217 canister filters or similar. Almost all problems with Oscar health come down to poor environmental conditions -- not enough aquarium space, not enough filtration. Cheers, Neale.>
<<Neale, WWM referral? B>>
Re: Astronotus; health   12/25/11

I noticed my temperature was off and that made him go back to normal color... but now the big one keeps swimming on his side. basically these to fish belonged to my friend who could no longer care for them. He housed them in a ten gallon tank and passed them to me. I can't afford a bigger tank at this moment, and the Oscars are very small.
<Hello again Nicky. There's really not much else I can say here. I appreciate you're doing your best to help these fish, and that you're stuck with the aquarium you have for the short term. But Oscars aren't "social" fish and won't get along without plenty of space. Males are aggressive towards one another *and* towards unreceptive females, and mouth-to-mouth and mouth-to-flank interactions are common examples of aggression. In terms of water quality, you need to keep nitrite and ammonia at zero, and nitrate below 20 mg/l, so heavy filtration and likely water changes more than once a week will both be part of the maintenance regime. Do read:
http://www.wetwebmedia.com/fwsubwebindex/oscars.htm
Cheers, Neale.>
Re: Astronotus; health, and comp. f'     1/5/12

Okay one last question it's, my big Oscar has almost killed  my smaller Oscar. My smaller Oscar's scales are ripped all the way off. Leaving white dermis. He can't eat anymore because he can't swim to catch food. His fins have been ripped between the connective areas. He is on his side and can only breath. So i put him in a fish carrier. There is a heater as well in there. He has been in there for the past week and a half. My main question is, is there a way to supplement his diet, since he can't eat. Vitamin drops???! I put Melafix for the fins.
<Melafix is not helping here; you need a proper antibiotic or antibacterial, e.g., eSHa 2000 or Maracyn. Vitamins are irrelevant. This fish needs a hospital tank (at least 30 gallons for an Oscar) with a heater
and filter where it can recover for a few weeks. Long term, each Oscar needs at least 55 gallons, preferably 75 gallons. As I've said before, Oscars are not social and yes, the bigger one will want to kill the smaller one. Putting the fish in a "fish carrier" (whatever that is) won't help. If you can't do any of what's required, euthanasia may be the only option.
Possibly, a pet store could take one or both fish from you, or you could make an appeal on a fish club forum or at a city aquarium club. Cheers, Neale.>

Jack Dempsey and Oscar in 60 gal tank   7/25/11
Hi! First off, great website! Lots of useful information.
<Thanks for the kind words.>
Anyway, I recently bought a JD, an Oscar, a convict and a green terror for my 60 gal tank. They were all of the same size.
<"Were" being the key word. These cichlids all have very distinct requirements and adult sizes. While Oscars and to a lesser degree Green Terrors are soft water fish, Convicts and JDs need hard, alkaline water, so you shouldn't be keeping them in the same tank anyway. On top of that, Oscars are fairly mild, Convicts territorial and aggressive but limited in size, Green Terrors potentially pretty nasty but compatible with Convicts and JDs, and JDs generally not too nasty until sexually mature but can be extremely aggressive. What you have appears to be a random collection of cichlids rather than species chosen because they will get along. Do, please, read one of the many excellent books on cichlid aquaria.>
Everybody seems to get along except for my JD who keeps bullying my Oscar.
What can I do?
<Not much. Your tank is too small for a random cichlid collection. A tank divider will work in the short term, but unless you have 150+ gallons, I wouldn't put much money on this bunch of rogues getting along indefinitely.>
Sent from my iPhone
<Sent from my computer. Cheers, Neale.>
Re: Jack Dempsey and Oscar in 60 gal tank   7/25/11
Any books you could recommend that would say which cichlids can live together?
<Hmm'¦ well, 'The Cichlid Aquarium' by Paul Loiselle is perhaps the benchmark, but it's a text for advanced aquarists willing to read scientific as well as aquaristic information. It doesn't necessarily say which species would work in a given tank, but instead provides you with the knowledge you need to make predictions. 'Pocket Professional Guide to Cichlids' by David Boruchowitz is easier to read and more "American" in tone (there's a marked contrast between German aquarium books and American aquarium books when it comes to style and content). It's well regarded and a fine alternative to the Loiselle book. Once you start concentrating on cichlids from particular areas, then you probably want to hunt down books by authors known for their expertise in those areas, for example anything on Malawian cichlids by Ad Konings is likely to be well worth reading.>
Sent from my iPhone
<Really? Won't Steve Jobs be pleased! Cheers, Neale.>

Oscar, comp.  -- 05/30/11
hi again
<Hello,>
I have a new 500 litre tank
<...132 US gallons'¦>
and I was thinking of getting a large albino Oscar around 25-30 cm. I already have 3 Oscars around 10 cm and a common Plec 18 cm. I am well aware of the Oscars reputation of anything it can fit in its mouth it will eat
<Indeed.>
so I just wanted to ask would I be able to put the smaller ones in with the larger Oscar or will he eat them
<Eat them, no; bully them, quite possibly. Your tank is a good size, but I think you're pushing it for more than one Oscar or a pair of Oscars. I suspect that if the ones you already have pair off, you're going to have problems.>
and the same with Plec or is it best just to keep them separate for the time being.
<Plecs are not the best companions for Oscars; there are numerous reports of at least some Plec species -- usually Pterygoplichthys species -- "sucking" onto the flanks of the poor Oscar, and causing serious damage.>
thanks again ysabella
<Cheers, Neale.>

Oscars... Incomp. w/ Af. Cichlids  - 2/9/11
Hello I've had 1 male and 1female Oscars together for the last four years, and recently the male died while we were moving house . she wont eat and looks very depressed its been 4 days now she usually eats several times a day!
Would you think a 5inch blue cobalt
<Cobalt what?>
would be ok to go in with her. Thank you for your help from narelle the fish lover
<Mmm, not likely... Depending on the size/shape of this system, other neotropical cichlids might go, and others. Read here: http://wetwebmedia.com/FWSubWebIndex/oscarcompfaqs.htm
and the linked files above. Bob Fenner>

Veil Tail Oscar    8/6/10
Hi crew,
<Hi Claire! Melinda here tonight!>
You have a fantastic site here, thanks for all the great articles! I have had a good read through the Oscar FAQs, however I can't seem to find an answer to my question. (forgive me if I have just missed it). I have a single baby veil tail Tiger Oscar. I have had him (he looks like a he to me anyway) for about three weeks. He currently lives by himself in an 80 gallon tank. He seems to be thriving. He has a great personality and has, I think, about doubled in size already.
<That sounds great.>
I have been starting to think it might be nice to have one more fish in there with him.
<Ahh. The "one more fish" syndrome. Is simply a precursor to the "one more tank" syndrome!>
I was hoping I might somehow get away with having another decent size fish. From reading through your articles and others, it seems the best time to do this is when the Oscar is still young, so I thought I had better make a decision soon. I figure once they start growing, if the 80 gallon tank becomes too small, I can always upgrade it.
<There you go. Already starting on "just one more tank.">
Cutting a long story short, as he is a veil tail, will he have problems defending himself against other fish?
<Perhaps against other territorial fish, but few of the fish you list below would cause a problem. I do worry about bioload, and without knowledge of this tank's filtration/your maintenance schedule, would hesitate to suggest any addition. Oscars just take up a lot of "room," volume-wise, on their own. Just test regularly and keep an eye on Nitrates. Under 20 is best.>
I dont want to add anything to his tank that will just terrorise him. What are the chances he would be able to get along with another Oscar or another Cichlid of some kind?
<I think unless you are able to find him a female that he likes, another Oscar is out of the question. As far as other Cichlids, I'm guessing you mean larger Cichlids, and I wouldn't advise it.>
Would common dither fish like Silver Dollars, Tinfoil Barbs, Clown Loaches or Bala Sharks nip at him?
<Silver Dollars can be nippy, but I have a group of 8, and have only witnessed them nip at each other. These "nips" quickly heal with good water quality. A small group (4 or 5) of the spotted type, which grow smaller than the more-common Red Hooks, could be kept in this tank, and would grow large enough to avoid predation. However, Silver Dollars can be quite flighty, and have a tendency to bash themselves on the glass in smaller, non-heavily-planted systems. This is an issue with Oscars, who tend to uproot and rearrange any imitation or live plants. Clown Loaches grow too large for this tank in the long run, thought they do grow slowly, and are quite easy to hand off to other fishkeepers. They would have to be quite large at the time of purchase, though, because they do grow slowly. I would purchase individuals at about three to four inches in length to avoid them becoming dinner for your Oscar in eight months or so, and even then, I'm not sure they could keep up. The trouble is finding larger individuals. Bala Sharks grow very large, and faster than the Loaches. In addition, they're even more skittish than the Silver Dollars, and even if you could keep the tank heavily planted, they could end up damaging themselves.>
Also, I understand that dither fish such as these would need to be kept in a group. I know these fish get quite large themselves. Am I right in thinking that I am going to run into more issues with water quality if I try to keep a group of fish, rather than focus on just two fish?
<Well, a group of smaller fish vs. a large fish is essentially the same bioload. For now, to tell you the truth, I'd leave this guy alone. If, in the future, you choose to upgrade, you could add a school of dithers with no problem. The issue with these large fish is finding fish buddies who are too large to be eaten, but yet won't overwhelm the system. In an eighty-gallon, it's a touchy subject. Since we don't yet know if he's a "he," you'd have to add a group of small Oscars and wait to find out who pairs up, and this isn't guaranteed to be pleasant or effective in this tank, which is large for a lot of fish, but small for Oscars, especially as they mature.>
What do you think would be my best option?
<Personally? I've got a male Green Terror in a heavily-filtered 75 gallon and he loves it, I love it, everyone who sees it loves it. And he's much smaller than your Oscar will grow to be! There's something special about having a "wet pet" who's catered to and loved as much as can be -- they grow larger, are more in tune to the humans outside of the tank, and are generally better pets. I'd leave him as he is in this tank. If you happen to upgrade, as you mentioned, to a 125 or so, then a school of dithers would be a good option. I know the tank looks empty right now, but give it a few months. Do ensure filtration is up-to-par for him -- he'll ultimately need a filter (or combination of filters) which turns the tank's volume over 8 to 10 times per hour, and that in itself can be a task. Do write back if you have any further questions.>
Any insight would be most welcome! Thanks for your time! Claire
<You're welcome! --Melinda>

Cichlid questions (jewel cichlid <repro.> and Oscar <comp.>)    7/1/10
Hi.
<Hello,>
My friend has a breeding pair of Hemichromis bimaculatus and they have spawned a few times already.
<Oh dear. Much as I like these fish, the market for the 1000s of fry they produce is tiny. Like Convict cichlids and "Tilapia", these are fish to breed when you have a market for the fry, rather than the other way around, i.e., breed them, and then look for a market to sell on your fry.>
Some time ago, he gave me 6 juveniles and told me to wait until a pair forms and then take out the rest.
<Yes, but why breed siblings? Among other things, the more you do this, the worse-looking the fry. Let them spawn if you must, but wash the eggs down the drain and/or euthanise the fry.>
As of now, the largest two are reaching 2.75 to 3 inches in length with the others being a bit smaller. Now these two larger ones are now hanging out at a particular corner of the tank and have even dug a pit in the substrate
already.
<Likely paired. This species can spawn when it is notoriously small.>
However, these two aren't showing aggression towards their tankmates yet and still let the other jewels swim into their corner and they don't chase them away. Is it time to take away the others?
<Depends. Unless you really want to rear the eggs, then I wouldn't bother. I'd just keep removing the eggs whenever they're laid, which will be more or less constantly if you keep them too warm. Hemichromis spp. are usually maintained at about 22 C/72 F, and up to 25 C/77 F only for spawning. Lower the water temperature and they'll spawn less and be less aggressive. I assume you know this, and have chosen tankmates with similar water
temperature requirements.>
Or should I wait for their territoriality to kick in to be sure that they're already paired up? The tank has other hiding places away from the potential pair's nook so I'm sure that if aggression starts, the others have places to retreat to.
<Indeed. Personally, I'd say this about Hemichromis. Unless you have a wild-caught pair or a pair of captive-bred fish that AREN'T siblings, keep just one. Both sexes are pretty, so one male or one female would be a fine addition to a spacious, rough-and-tumble community. There is ABSOLUTELY no point spawning Jewel Cichlids unless you have a DAMN good reason to do so. You won't be able to sell the offspring, and nobody really wants (or needs) poor quality, genetically dubious offspring produced by mating a brother and sister.>
Also, I'm planning on getting an Oscar. This will be a separate tank from the jewels, of course.
<Indeed. Hemichromis require cooler water than Astronotus.>
I'm a bit curious if there are other cichlids similar in behaviour and size as that of an Oscar. I'm planning to keep a lone fish only. Will a green terror do?
<Wouldn't be my first choice. For one thing, Aequidens species require relatively cool water, 20-24 C/68-75 F depending on the species. Instead look at Severums, especially "Rotkeil" Severum, Hero appendiculatus.
Another good choice is the Festivum, Mesonauta festivum. Of course it depends on the personality of your Oscar; some are mild and will work with Severums and Festivums just fine, especially if the tank is a sensible size, 150 gallons upwards. But a grouchy Oscar, or an Oscar cooped up in a 75 gallon tank won't take well to any cichlid. So do remember you need at least 75 gallons just for the Oscar and maybe a catfish, and any addition cichlids will want territory of their own. Don't discount Climbing Perch out of hand; I've seen Ctenopoma kingsleyi for example kept with an Oscar in a large aquarium, and the contrast between the brown/copper on the Oscar and the green/turquoise on the Climbing Perch was lovely. I might also mention the warmer-water geophagine cichlids such as Geophagus jurupari (more properly, Satanoperca leucosticta) but these get sick at the first whiff of nitrate, so unless you have [a] a massive aquarium; [b] perform regular water changes; and [c] can keep nitrate levels below 20 mg/l these interesting cichlids won't work.>
Somebody suggested to me a Flowerhorn but I'm not fond of them.
<Me neither. In any case, they require completely different water chemistry to the Oscar.>
Thanks, WWM.
Gabriel
<Cheers, Neale.>

Black Ghost Knife and Oscar tankmates. Holy incomp. Batman!  -- 02/14/10
Hello,
<Hello,>
I have a 55 gallon tank with a 3" Albino Tiger Oscar, a 5" Black Ghost Knife and a 3" common Pleco.
<Overstocked already.>
I would like to get some other fish to keep with them. I would like to know what types of fish my tank would accommodate with respect to a) bioload, and b) temperament.
<Nope. Even by itself, the Plec is going to put a really heavy load on the aquarium. Add an Oscar, and things get dirty pretty fast. An adult Black Ghost as well? No way.>
I was thinking maybe even an Electric Blue Jack Dempsey because I read that the Electric Blue was a genetic defect that generally made for a less aggressive and smaller variety than the standard Dempsey.
<Heard rumours about its lesser aggression too, but frankly, this is still a crashingly bad choice for this tank. Central American cichlids have very specific requirements, and mix poorly with South American ones.>
I wanted to confirm that assumption before I bought one. My Oscar is a very passive fish, however, I do understand that they get more territorial as they mature. Would the EBJD be a suitable tankmate?
<No, it wouldn't.>
This would really be my preferred option as I like the more sturdy, larger fish. Is there a breed of cichlids that I could maybe put another 3-4 fish in this tank peacefully? I know you may not like it for it's size, but I will be upgrading to a large canister filter soon and would really like to have a few, more interesting fish.
<I think you need to review the needs of the fish you have. An adult Black Ghost is upwards of 50 cm/20 inches in length, and extremely sensitive to poor water quality. Most folks fail to keep them alive for more than a couple of years. When was the last time you saw a full grown specimen?>
As for dither fish; what would you recommend? I've read where you have advised Clown Loaches and Angel fish, but I would like something a little more exotic. Silver Dollars are okay but I've read that they can be a little nippy. Could a few Bala Sharks or Serpae Tetras cohabitate with the fish I already have?
<Serpae tetras are FAR too nippy to mix with any of these fish.>
Are there any freshwater puffer fish that would survive with these fish?
<Repeat after me: puffers aren't community fish, puffers aren't community fish. By all means keep a puffer, but in its own tank. South American puffers and Carinotetraodon irrubesco are the two species that might be considered, being relatively peaceful. But SAPs are too nippy to keep with Oscars, and adult Oscars would simply view them as a potentially edible nuisance. As for Carinotetraodon irrubesco, this species would also be Oscar food, even though it isn't especially nippy.>
Thanks in advance for the help. It's very much appreciated.
Joshua 

Oscars, Tank size, Tank mates
Creating an Oscar Tank 2/4/2010

Hello everyone, and thank you for the excellent advice as always. I'm thinking of buying a 125 US gallon tank to put tiger and albino Oscars in (Moderately planted with plastic plants, caves, Fluval canister filter, 77 degrees Fahrenheit, driftwood). Do you think six specimens would be reasonable, without fighting and overcrowding?
<The overcrowding may not be a problem with proper maintenance, but the fighting issue may be out of your hands. When you buy six cichlids you have a 98% chance of getting a breeding pair. When these fish pair up and spawn they are very protective of the eggs and fry. They will guard the area next to the eggs, but when the fry become free swimming the fry disperse throughout the tank every fish will be looked at as a threat and will be attacked by the pair.>
Also, I'm thinking about moving my Pleco (approx. 9 inches?) to the tank as well. Would a Senegal
bichir fit in with them alright?
< The Pleco would be looked at as a threat if it wanders into the Oscars territory, same with the bichir.>
I would be feeding the tank Hikari cichlid staple and frozen thawed bloodworms daily, along with earthworms about twice a month. Excited about them, love the personality of cichlids. Thanks!
-Jack.
< Forget the bloodworms, stick with the pellets and use the earthworms as planned. .Look at getting the book, "Enjoying Cichlids" by Ad Konings for some insights on mixing cichlids.-Chuck>

Oscars? Not mixing w/ goldfish   1/5/10
Hello WWM crew,
<Kaitlynn>
I have been thinking of buying an Oscar for a while now and have done a good bit of research on them. My family and I have a 5 gallon tank, (which is mine), a 50 gallon tank (my mom's), a 90 gallon marine aquarium (my
dad's), and then a 500 gallon, above ground Koi pond. Altogether we've all had a lot of experience with fish of all kinds, and so I wanted to try out an Oscar, keeping in mind how large they get and how long their life
expectancy is. My plan was to buy a baby Oscar (or two or so), and put it in my mom's 50 gallon tank, which is currently housing two very large Ryukin goldfish,
<No... don't do this. Though these fishes have similar "likes" in terms of water quality, except for temperature... Their temperaments make them incompatible>
and a very large Black Moor goldfish which are all about, or bigger than the average tennis ball. I was wondering if they would be at least "okay" tank mates with a small 2-4 inch Oscar until it outgrows that tank, and then from there hopefully I would have saved up enough money to buy myself a nice large tank around 100-175 gallons, since I'm also thinking of perhaps breeding them in the future, but if not then I planned on keeping it with the Koi until I did have enough money. Any ideas and or suggestions for me? Thanks
Kaitlynn
<I'd wait till you have another tank available. Please read here:
http://wetwebmedia.com/FWSubWebIndex/oscars.htm
and the linked files... Systems>
P.S. How aggressive are Oscars, on a general scale?
<And Compatibility. Bob Fenner>
Re: Oscars? Comp., stkg.    1/11/10

Okay, thanks for the advice, I decided to wait until I have my house to get an Oscar anyways since they'd require quite a large tank. Thanks again!
-Kaitlynn
<Real good. BobF> 

Catfish problems 9/29/2009
Hi crew! I have a 4 1/2 inch Pictus Catfish who recently was accompanied by a South African Cichlid (species is unknown, was an adoption fish).
<I see. Do try and send us a photo, and we'll put a name on the cichlid.
There aren't many cichlids native to South Africa as such, and I wonder if you mean a South American cichlid? South American cichlids are generally fairly placid and get along fine with catfish, but East African cichlids, by which we usually mean Rift Valley cichlids, usually can't be kept with catfish. They are far too territorial and aggressive. Moreover, Rift Valley cichlids require much different water chemistry conditions to South American catfish such as Pimelodus pictus. One last thing: Pimelodus pictus are schooling fish, and really shouldn't be kept in groups less than three.>
The Cichlid was fine with the Catfish, didn't bother him at all until a few days after we received him.
<Often the case. Initially the cichlid was exploring the tank and figuring out who lived there. With that done, and once the cichlid feels secure, it becomes territorial, and that's usually when trouble starts. Juvenile
cichlids are less aggressive than sexually mature cichlids, so that's another reason why a peaceful cichlid can suddenly appear to turn nasty.>
He started to turn on him, chasing him from one end of the tank to another violently ramming and nipping at my Catfish. The following day after it had happened I said enough is enough and took the Cichlid back to the store. My Catfish is now bruised and hurt, and I really hate to see him like this.
<Indeed!>
He behaves normally and eats properly, but I was wondering if I could possibly put an Oscar fish in the tank with him when he is all better? I know Oscars can be aggressive at times and will eat smaller fish, but if I
bought one as a teen, maybe 2 inch long, would my Catfish and the Oscar be compatible?
<Depends on the size of the Oscar. Adult Oscars view catfish as food: their strong jaws evolved to crack open hard prey, mostly crabs, crayfish and snails in the wild, but occasionally small catfish as well (apparently Corydoras!) So I wouldn't risk a small Pimelodus pictus with a big Oscar. A juvenile Oscar would be fine, I'd just be wary about a full-grown specimen.
Be careful with Oscars though; they are huge fish, and expensive to keep properly. Not fish to buy on impulse! Pimelodus pictus actually work much better with non-aggressive South American cichlids of medium size, including Angelfish, Severums, Eartheaters, and so on. Medium to large Gouramis are also good. Of course, Pimelodus pictus are predatory themselves, so very small (or baby) tankmates would be a bad idea.>
I am sorry for my ignorance in this area, I am 13 and have only been keeping aquariums for 9 months now.
<Welcome to the hobby! Hope everything works out. Cheers, Neale.>

Oscars in same tank with electric blue jack Dempseys  7/12/09
Hi,
<Hello,>
We have a year old 10inch white albino Oscar and a 4 month old 7inch black tiger Oscar in a tank with a Pleco and a Hoplo sternum cat fish.
<I see.>
I have recently learned about the electric blue jack Dempseys and absolutely love them.
<As do many. But they're no different to any other Rocio octofasciata --
quite big, very aggressive, highly territorial, and requires hard rather than soft water.>
I want to know if these can live together I will be adding my baby red Oscar when he gets larger as well.
<On the whole Rocio octofasciata will be tolerated by substantially larger Astronotus given sufficient space; on the other hand, Astronotus are not aggressive fish and do not like fighting, and juvenile Astronotus will be bullied, even killed, by larger Rocio octofasciata. So it all depends on the size of the aquarium and the relative sizes of the fish. One thing to remember though is Astronotus prefer soft water, while Rocio octofasciata must have hard water; so your water conditions are a factor.>
Also what size tank do I need I know the larger the better but any ideas on what size 120 Gal?
<For three adult Astronotus and one adult Rocio octofasciata, you're talking about 200 gallons, minimum.>
I know its possible for these two types of fish to live together as a friend of ours has a 400 gal tank with four Oscars, two red belly piranhas, two pacoos and two jack Dempseys.
<Your friend is insane. Piranhas shouldn't be combined with big, aggressive fish, and since they're either kept singly (most genera) or in groups of 6+ specimens (all Pygocentrus, some Serrasalmus species), keeping two makes no sense at all. Pacus (Colossoma spp.) are far too large for home aquaria, and will eventually outgrow this aquarium; they are also much more aggressive and predatory than people expect, and we recently had an e-mail from someone with a Pacu that attacked and killed an Oscar. So once these two Pacus get to full size -- potentially 100 cm in length -- the Piranhas will very likely be bullied or eaten, and the other fish may well be injured at some point.>
I am guessing he got away with it because of the size of tank he had. Any suggestions would be great thanks.
<Read, learn, think carefully before combining fish species.>
Rachelle V
<Cheers, Neale.>

Oscar isolation
Oscars Not Getting Along -- 07/01/09

Hi There, First let me congratulate you for your excellent web.
< Thank you for your kind words.>
Now the question. I have two medium size Oscars and a Pleco in a 75 gallons tank.
The biggest one is a red Oscar and the other a tiger.
Initially I acquired two little red Oscars, cute ones and a Pleco, but I didn't realize that the Pleco was infected by ich. So, as you imagine after a couple days, the ich was everywhere. I treated the Oscars and Pleco with anti-ich stuff and high temperature, but the ich took away a victim with it. The victim- one of the little red Oscars. .After this tragically incident I found company for the red Oscar and Pleco. The new family member...a tiger. Although the tiger was half of his size, they got along very well for almost 5 months. But now, everything has changed, both Oscars started to fight menacing each other face to face with mouths wide open until the smallest won the contest and became the dominant fish. Now both of them are damaged but the big red Oscar refuses to defend himself. Their favorite food is live crickets, chicken, krill and tetra cichlid sticks (don't like them as they pollute the water),they used to eat any sort of commercial food but now they reject it. So, not sure if it was the chicken and crickets that turned them that aggressive or is just bad luck. I isolated the tiger Oscar for a day in a very small prison-aquarium . After that the red one started to attack the plants(seriously) as if he was fighting with the other fish, but now he is confident and looks better, not afraid anymore. But I'm afraid that when I will put the tiger back, he will continue to harass the red Oscar.
Question:
-Should I find a new home for the tiger? Rather than sending him to his mini-jail.?
< Oscars are cichlids that get to be territorial. They could be trying to pair up with a dominant male and a reluctant female that is not ready to spawn. Or it could simply be two males with too much testosterone defending a territory against all other fish. At this size you may not be able to put them back together. Lower the water temp to 75 F and rearrange all the tank decorations. Late at night try to put the two Oscars together. Don't go away. They may start to fight right away. You could then put a glass partition in the tank with one on either side. They will continue to flare at each other but not inflict any damage. This may be better than a mini jail.>
-Did their diet affect on their behavior?
<Fish that are in good shape are more healthy and better able to set up and defend a territory A varied diet will improve their health and their vigor It might have had something to do with the increased aggression..>
-If I take the tiger away , what would be the best company for the red Oscar?
< Already the Oscar is rearranging the tank. It will probably not tolerate any other fish. Another cichlid would be seen as a threat. Might try some fast moving schooling fish like a school of tinfoil barbs.-Chuck>
Any answers are much appreciated. Thank you

Juvenile Oscar and Bristlenose Pleco -- 04/22/09
Hi WWM,
<Hello Alison,>
I have spoken to you previously about my Albino Red Oscar. He is in great health now and doing really well, however, we had started to get a build up of brown algae, which I learned is probably because his tank doesn't get a lot of natural sunlight.
<Diatoms have nothing much to do with sunlight. In cichlid tanks they're pretty common. Use a sponge or scraper to remove from the front glass. Fast growing floating plants under bright lights will also do much to slow down their growth.>
I decided to add a bristlenose Pleco to our 40 gallon tank, since they stay pretty small compared to the common Plecos.
<More "bite size" than a common Plec, I'd suggest. Oscars feed extensively on armoured catfish in the wild. That's why they have jaws adapted to crushing things, rather than snapping at midwater fish that otherwise swim to quickly for Oscars to catch.>
I ordered an albino and he should be here tomorrow. However I have started to worry that Oscar may eat our new fish, since the Pleco is only 3-4 months old and Oscar is about 4 1/2 to 5 inches now.
<If the Oscar can bite the catfish, it will do so.>
He is always hungry, but doesn't seem to be really aggressive.
<Aggressiveness and predation aren't related; piranhas are complete wimps in terms of personality, but they're remarkably capable predators; conversely, Mbuna are herbivores, but amongst the most psychotically aggressive fish in the hobby.>
He doesn't mess with his tank decorations or the heater, but does jump and beg for food when it is feeding time. He eats earthworms and wax worms with no problem, and large chunks of dried krill.
<All good foods for Oscars.>
I was wondering if I should not put the Pleco in with him.
<Depending on the size of the tank, a Plec of comparable size to the Oscar is fine. But don't for one second assume such a catfish will clear away any algae. It won't. All a big catfish will do is make maintaining water
quality more difficult, and that it turn will speed up the growth of algae.>
My daughter also has a small tank with two goldfish, with no algae though.
Do you think it would be giving him a 12 dollar snack?
<Maybe.>
I appreciate the any advice you have. Thanks! Alison
<Cheers, Neale.>

125 Gallon
Tankmates For Large Oscar 4/18/09

Hello, I have emailed you guys before and thanks for the great advice in return. My issue that I have now is that I am going to set up a 125 gallon tank that is going to be centered around the tiger Oscar that I have now who is about 9-10 inches in size and needs a larger tank. Knowing that this is a fairly large tank I would like to add more fish to it besides my Oscar. The set up I think I may go with is the following; My tiger Oscar, a pink veil tail or a Jack Dempsey around the same size as my Oscar, some quick schooling fish (about 6) either being large gouramis or barbs and a nice sized Plec that would be able to handle being in the tank with the large cichlids. Another set up that I though of would also consist of my Oscar but I would like to add maybe two more South American cichlids rather than the schooling fish and a Plec. Either way I would like to add at least one more large colorful cichlid to the tank if not more than one such as a jack Dempsey, another Oscar, green terror, etc. But by all means I plan to set up this tank with the size of the fish and/or the aggression level to be pretty similar so that I do not end up with any hurt or dead fish. Could
you please send me something in return ASAP about the compatibility of these fish and anything else that you see helpful. Thanks a lot for the help I have received in the past and I look forward to seeing the crew's
response to this matter.
< Getting your Oscar a large tank is a good idea. Ideally all the fish should be small and grow up together. Too late for that now. Adding adult cichlids will cause trouble until a pecking order is established. Some torn fins and damage will be expected. A school of large fast barbs would be best. All the cichlids you have suggested can inflict damage and will be aggressive. Mixing adult cichlids is very tricky and greatly depends on the temperament of each individual fish. Less aggressive choices would large Eartheaters, chocolate cichlids, Severums, to name a few.-Chuck>

Ask WWM - compatibility, of course
Oscar Tankmates  4/14/09

Hello, I have read many of your answers to questions, and I think my Oscar situation is a bit simpler than some that are posted. I have a 90 gallon tank with just one ugly, but well loved and happy, albino Oscar. Oscar is about 8 inches long, one year old. Oscar likes me more than anyone, I can occasionally touch him but he is leery of strangers. If he is upset he plays dead at the back of the tank (such as when my ridiculous boyfriend sticks his arm in the tank!) and occasionally after cleaning the tank he shows he is upset by puffing gills at me. For interest sake one day, I held a mirror up to the tank and Oscar again played dead at the back of the tank so I think he's a bit of a coward. I do feed him small rosie feeders from time to time, which he hungrily chases and eats. I also had a snail, which he ate only when I was away for a weekend. He stopped 'redecorating', pulling plants, and spitting rocks when he was moved from a 35 to the 90 gal 4 months ago (after which he grew an inch or so), so I believe Oscar is happy and relatively easy going. I conduct 25% water changes with gravel siphoning every week or week and a half. I only have plastic plants and regular rocks in the tank. I have an overhanging filter (good for 110gal), which I may replace when I have some extra money or in a few years.
I am very happy with Oscar, and want to maintain a simple tank. I am considering purchasing one or two tankmates. I have seen in your answers to other questions that some compatible fish are clown loach, Festivum, Severum, silver dollar (school of 6), chocolate cichlid (group of 3), jurupari (group of 3).
I am from a small town with limited pet stores, but I think the store I would purchase from has an okay variety available. One of my concerns is that I do not know that I can easily identify these types of fish at the store, but hopefully the people there know what they are talking about! The manager has told me 1) a pair of one type of fish might introduce problems, especially if they are a breeding pair, so I should just purchase two different types of fish that are appealing and b) choose from the silver dollars or cichlids, obviously at least 6 inches so Oscar doesn't eat them. I know that the store has convicts, silver dollars, Firemouth meeki, yellow-coloured cichlid (I think), and I think green terrors and/or some that look like web images of the green terror with that type of spotting (some seem more blue, some more orange, but with similar spotting). They may have Severum, and clown loaches.
I now understand from your other postings that silver dollars need to be in larger groups/school. I also know that I should try and confirm with the store manager that I am purchasing a South American Cichlid. My question is then, what type of (common, and likely readily available at the store, by your approximation!) South American cichlid or other type of fish could I put in my 90 gal with Oscar? If I purchased 2 or 3 fish, how would my choices change? Are silver dollars truly happier in large groups?
I am easy to please! I just want another body or two in the tank, if possible'¦but FYI, I do not have any algae to sustain a Pleco, and I do not like Parrot fish! Of course, I need to ensure they all require the same tank conditions - I know I need to drop the temperature a bit when adding fish, my tank is on the warm side for Oscars. I will not be upgrading the tank size.
When I add the fish my plan is to 1) take out all plants and rocks 2) conduct a 40% water change 3) clean the filter, change whichever media is due for change 4) replace plants etc in a different arrangement and add my new shipwreck complete with hiding places 5) add the new fish 6) keep the lights off for a couple days, and stay home for a couple days to watch what happens. Is this a good game plan?
Thank you so much for your advice. It is extremely difficult to get consistent advice as I'm sure you well know, and store owners tend to just want to sell you stuff, not help you. I am a graduate student, so I take great solace in the peaceful company of my fish, and I do not have cash to upgrade much further! Thanks again! Meghan Moran
< This tank is your Oscar's territory and he will never be happy with any additions to his tank. Other cichlids will be instantly be push around in a test of dominance. The new cichlids will have to fight back to get any foot hold in the tank and there may be damage to both parties involved. Cichlids that you mentioned will tolerate the Oscar's water conditions but the best you could hope for is a truce between the tankmates until one of them gets sick or injured. The other option is to add dither fish. This is a term used to describe tankmates that are too fast for your Oscar to catch or eat. A school of fast swimming open water fish will never be caught. Silver dollars have the added advantage of the shape of their body will not allow them to be eaten. In an ideal situation you should have gotten the fish young and allowed them to grow up together. This way the pecking order would have been established while the fish were young and could not inflict too much damage on each other. With an adult Oscar you will need a group (6) of some large fish. This will increase the bioload on the filter. You will need to do more water changes or larger water changes to keep the nitrates under 20 ppm. Your pet shops may not have these fish available. When you get them I would try to add them all at the same time.-Chuck>

Re: Ask WWM - compatibility, of course
Clown Loaches As Tank Mates For Oscars 4/18/09

Thanks, I understand what you are saying, and you are probably right. What about some dithers such as Spanner barbs, or 3 or so clown loaches? Will loaches take cover in hiding spaces if necessary? Are loaches fast moving? Meghan
< I would go with the fast moving barbs instead of the loaches. Since loaches hang around the bottom they can be pinned against the sides or the bottom. They carry a secret weapon in a small sharp spine under each eye. They are not as fast as the barbs.-Chuck> 

Three Oscars in a 55 Gallon Tank   2/25/09 Hello, I have been reading over your website, and many, many others. I have recently purchased a 55 US gal aquarium. I initially set it up with the standard filter system that it came with. The aquarium is a TopFin brand. I set it up and let it stand with filter running for the cycle period, approx 2 weeks. I did my water tests with API drops for those two weeks, and all looked good. I then went and purchased 3 gouramis.. I kept an eye on it, and got the expected ammonia spike, which rectified itself with in three days. The fish were all healthy, then I made the error of buying two spotted catfish from our local Wal-Mart. With in three days I had parasites and ich. I did all I could with medication for ich and parasites, 25% water changes weekly and feed every other day and removed the carbon element in the filter. Kept the temp at 75-76 degrees. I was unsuccessful, as the fish did die. I then sterilized the tank and decorations according to one website, and let the tank re-cycle for two weeks. Now I have three Oscars. I purchased one, and the other two were given to me, or faced being flushed by their previous owner. My question I have is this. Can I support three Oscars in a 55 gal tank? <Eventually the Oscars will grow and only one will be able to live in a 55 gallon aquarium.> Since I got the additional two Oscar, I have added a aqua cycle 70 filter, the type that has the sponge, then the carbon and then a bio pellet bag. I have been over dozens of website and talked to three of my local pet supply stores. No one can give me the same answer twice! I really don't have the room or money to purchase another tank, nor do I want to get rid of my Oscars. (by the way one is a red Oscar, Midnight, one an albino Oscar, Chalky, and one is a tiger Oscar, Duke.) I make sure I test the water weekly, and do a 25% water change weekly, and along with the water changes add aquarium salt per instructed dosage. So far they are good, the water test are showing that ammonia is 0ppm, nitrites are 20ppm and the nitrates are 15ppm, both of the nitrates and nitrites are slowly going down, and I keep the temp at 80 degrees F. ( I have had them for about two weeks now) The three Oscars are currently juveniles, no longer than 1" to 2" long. They are currently healthy and active, especially when feeding. I use a brand of Cichlid pellets, supplemented with freeze dried brine shrimp, and I make sure that they all get plenty of food. I have not seen them fighting, other than the occasional mouth biting, and they seem to be doing good. At night they all clump together behind a tall fake plant. I do need to get more cover if I can keep them, which I plan on doing after I read your response! I have read many horror stories of having too many Oscars and they get unhealthy and die. I have also read many stories of three or more Oscars living happily for many years in a 55 gal tank. I need some type of definitive answer as to whether or not I am setting myself up for heartbreak and disaster down the road, and dooming my Oscars to a slow and painful death because the tank is too small. Please let me know your thoughts, as I am very interested in your opinion. Your site seems to be very professional, and up-to-date. Thanks in advance Joe Leimbach < To keep your Oscars healthy you need to keep the nitrates under 20 ppm. The ammonia and nitrites need to be zero. Check the nitrates of your tap water. As your Oscars grow the nitrates will continue to rise. When they get to the point to where the nitrate levels go higher than 20 ppm between water changes then you start to have problems with Hole-In-The-Head and bloat. You then need to do larger water changes or more frequent water changes. Sometimes even both are needed. If you don't have the time nor the effort to do this then you need to reduce the bioload of the tank by reducing the number of fish. In areas with lots of agriculture the nitrates may be up to 50 ppm right out of the tap. This makes it very difficult to keep fish.-Chuck>

Tank Mates??
Oscar Tankmates   8/29/08
Hello there, I have emailed you guys before about some of my tanks and ideas about new tanks and have received great advice! Now I have a question about my Oscar cichlid who is about 8 inches long. I am soon moving him to a larger tank hopefully 75 gallons but maybe 55. And I was wondering about some tank mates for him. I am very interested in more South American cichlids. I have a particular interest in maybe getting a jack Dempsey? But I do know Jacks are pretty aggressive and territorial that's why I am consulting you guys. Another cichlid I was considering was a green terror but im not sure if the adult size of one could or would grow up to being as big as my Oscar because I have read that they only grow to be 8 inches in length. Lastly I was considering a blue Acara or a jaguar cichlid but my problem with these two are I have no idea how big they get. Could you please send me some helpful advice about this matter. Thank you.
< Oscars get up to a foot long. They are very territorial and another cichlid would lead to constant battles over turf. I would recommend instead using dither fish. These are large flashy fast fish that the Oscar will have a problem chasing around. They can go from giant Danios, tinfoil barbs, silver dollars etc... The fish need to be in large numbers of at least three for the larger fish to at least six for the giant Danios.-Chuck>

Tank Mates?? Oscar comp./sys., Neotrop. cichlids period   08/28/08 Hello there, I have emailed you guys before about some of my tanks and ideas about new tanks and have received great advice! Now i have a question about my tiger Oscar cichlid who is about 8 inches long and pretty docile. I am soon moving him to a larger tank hopefully 75 gallons but maybe 55. And i was wondering about some tank mates for him. <Not in the 55... too small> I am very interested in more South American cichlids. I have a particular interest in maybe getting a jack Dempsey? But i do know Jacks are pretty aggressive and territorial that's why i am consulting you guys. Another cichlid i was considering was a green terror but im not sure if the adult size of one could or would grow up to being as big as my Oscar because i have read that they only grow to be 8 inches in length. Lastly i was considering a blue Acara or a jaguar cichlid but my problem with these two are i have no idea how big they get. Could you please send me some helpful advice about this matter. Thank you <The Blue Acara will be/stay too small to be placed with the Oscar et al.... the others might be placed together in a larger system... introduced by using a divider twixt them for a few weeks, then being allowed to associate... with you present to separate again should there be troubles. Read here: http://wetwebmedia.com/FWSubWebIndex/neotropcichcompfaqs.htm and here http://wetwebmedia.com/FWSubWebIndex/oscarcompfaqs.htm and the linked files above. Bob Fenner>

My Oscar, damage... hlth. Hello... <Ave,> I am having a very serious problem with 1 of my Oscars... We currently have 2 Oscars, 1 albino tiger & the other Hong Kong, in a 75 gallon tank. <OK. For a start, Astronotus are not particularly sociable. If you have two males, the dominant one is likely to be pretty nasty the other one. Since Oscars cannot be sexed outside of watching them spawning, adding two Oscars to a tank is usually a recipe for disaster.> We have had them both around 2 yrs... 2nite when we were getting ready to feed them, we noticed than 1 of them was gushing what looked like blood out of the left gill. <Physical damage perhaps? Could be caused by fighting, though usually damage to the jaws and/or fins will be noticed before anything more serious. A photo would *really* help here because it's difficult to know what you mean by "looked like blood". Was blood seeping out of the gill covers (the skin on the head) or from the gills themselves, through the gill openings? Any damage to the gills is serious, and potentially lethal (cf. damage to our own respiratory system). Gills can also be damaged by poor water quality, as well as certain parasites, such as Velvet.> I tried to research to see if any one else has and this problem, but had no luck... I have fed them feeder fish in the past (many months ago), but this just recently started happening... <Well, don't use feeder fish, EVER. There are no benefits and many risks. Oscars have been tank-bred for generations, and will eat just about anything. By nature they are omnivores, and have very much a "suck it and see" approach to life, so I'd always recommend a nice mixed diet with lots of healthy chopped shellfish (such as mussels) as well a good quality cichlid pellet (like Hikari Gold).> If you could let me know if you have ever heard of this & how do I treat this so that my other Oscar doesn't get it... <Very difficult to say without a photo!> Thanks!! Tomeika <Cheers, Neale.>

Re: My Oscar  8/22/08 Well, my Oscar died last night after I sent you the previous e-mail. <Ah, too bad. I'm sorry.> We tried to treat the tank with some antibiotics that we had and he tried to fight whatever was causing him to die, but it just didn't work. <Rarely does I'm afraid. Unless you can positively ID the problem, randomly adding medications almost never works, and potentially exacerbates the problem.> He died around 4 this morning, yes we were up all night. <Oh!> Thank you for responding to me and next time I have any questions, I know where to go. <Well, sorry we weren't able to fix this. Do take care adding any other fish to this tank, because the resident Oscar will likely view other cichlids as threats. Do also review water quality, and look out for anything that might have caused physical damage, such as sharp objects as well. Good luck, Neale.>

Cichlids and Oscars -- 7/30/08 Hi WWM, My husband and I are in a bit of confusion and would appreciate any advice that you can give. We've been searching for the relevant information and can't seem to find exactly what we are looking for. My husband has a 5 ft tank with a 5 cm convict, 10cm jewel, 6-7cm blue cobalt and lombardoi, and (an extremely aggressive alpha) 10 cm peacock. The problem is my hubby loves Oscars and we did originally have 2 with these same fish (except the Lomb. and cobalt) and the tiger Oscar died about 4 months ago and the albino Oscar died in a friend's tank, while we moved and had to cycle our own tank, for no apparent reason (her tank was cycled and had had no fish in it at the time). I do have to say that the peacock did harass these Oscars (and the convict) repeatedly. Question: is it better to get 2 new "larger" sized Oscars to go into the tank, or should by husband perhaps get some more 'zebra' breeds like the cobalt and lombardoi, go for an extra jewel or could he get some Severums (he found your info on these fish and thinks they are great). However, Oscars are his passion-how can he have a happy tank with Oscars in it? Thank you for you advise. Tania <Hello Tania. The short answer here is "No, this won't work". For a start, Central American, Rift Valley lake, and South American cichlids have entirely different water chemistry requirements. Rift Valley cichlids want hard, alkaline water; South American cichlids want soft, acid water. Anything that suits one will be stressing the other, and there isn't a "happy medium" either. Secondly, Oscars are big but peaceful fish that don't do well in tanks where they are constantly having to defend themselves. By all means mix Oscars with big, peaceful catfish and characins, but please don't combine them with aggressive cichlids. Thirdly, keeping two specimens won't fix anything and could create new problems. Fish won't "gang up" to defend themselves just because they're the same species. A mated pair will of course protect their nest, but that's something else entirely. Fourthly, a full-grown Oscar could eat any fish under 10 cm long, which puts some of the existing fish in danger. While your collection of fish includes some lovely beasts, there's no logic to the combination of fish at all, and in fact plenty of bad choices. If it was me, I'd empty the tank, and then keep a South American community of some type with an Oscar, a Severum, a school of large characins (such as Silver Dollars), perhaps a Flagtail Prochilodus for fun, a nice Plec of some type, and maybe some sort of day-active, funky catfish like Hoplosternum or Callichthys. I'm just not a big fan of compromise tanks where none of the fish are really at their best and some of them a beating the heck out of each other. Cheers, Neale.>

In need of Oscar 'expert', beh., comp. Dear Crew, My Oscars are really starting to get super aggressive, but not toward one another! I have been bitten several times, these bites occasionally scratching deep enough to draw minimal blood. My Plecos are hiding in their driftwood with little tears in their fins. The air hoses are being torn out, decorations (heavy resin logs!) are being pushed around. Not to mention constant gravel throwing! This all sounds pretty normal... <Yikes... not uncommon behavior> I have two Oscars that are almost a year old (At least I believe so. They were about 3 inches when I got them in October 2007). One is an albino tiger about 11 inches long. The other is a red Oscar about 8.6 inches long. They really never fight with one another, but never leave each other's side. They shake their tails at one another and even eat together peacefully. I provided them with flat rocks and what not, thinking this would encourage egg laying. I don't know if I have a pair. From the pictures I've looked at and books I've read I think this is a possibility. I know sexing Oscars is difficult so I'm still not quite sure. The following picture is what they've been doing the past few days. I recently moved all the driftwood to one corner to allow the Plecs to hide and to give the Oscars more room to throw things around. They hate decorations so I figure I might as well make the tank the way THEY like it. View full size Recently the albino Oscar has some sort of tube extending from its anal area. This is not a prolapse as far as I know, because the tube is below its anus. I've included some pictures of the fish and their 'bottoms' to see what you guys think. At any rate the red Oscar's anal vent is not as distended as the albino's. View full size I apologize for the pictures being kind of poor. They get very upset when they see the camera and flare their gills and show me their mouths and all those cute Oscar threats. Thanks so much for your time! - Michelle <No pix came through. Please try attaching rather than embedding. The tube is likely a breeding device... I would remove the Plecos if they're getting too beat. You don't mention the size of the system, or what you feed exactly, but these are important factors re these animals behavior. Please read here: http://wetwebmedia.com/FWSubWebIndex/oscars.htm and the linked files above. Bob Fenner>

Oscar Fighting 3-24-08 Hello and happy Easter. <<Hi and happy-chocolate-bunny-holiday to you as well.>> I have had a tiger Oscar for about 6 months now that's about 3 inches, he has been living by himself for the most part but today I introduced another red Oscar that's a little smaller. <<The BMOC (big man on campus) aka your established Oscar will not take kindly to that, even in larger systems.>> The tiger Oscar has an area that he always goes to when I have my hands in the water, like a shelter. Since introducing the new Oscar whenever the new Oscar goes anywhere near that half of the 55 gallon tank he pushes him in the side with his mouth, like he's ramming him. <<Aggression, yes'¦is expected.>> I have somewhat rearranged the territories and the tiger Oscar leaves the new one alone while he's in his little hut that I made for him. Since then the red Oscar has been hiding there. My feeling was that the tiger Oscar got used to having the tank to himself and that was the main reason of him showing aggression towards the new Oscar. <<Yes'¦he viewed the stranger as an intruder on his territory.>> My worry is if they keep fighting then the new one will die. <<A valid concern. When we consider their adult size this is a temporary set-up at the best. I would watch them cautiously and be prepared to remove one or the other if aggression ensues as it will only get worse as they age. You could attempt to quarantine the older Oscar away from the display for a few weeks in order to disrupt territory disputes, but there is no guarantee and this is again at best temporary. >> Thanks in advance, <<Anytime.>> Tommy <<Adam J.>>

Baby Jack Dempseys With Full Grown Oscars - 02/06/07 Hey Guys. Just wanted to say I like the site, works for me. I was hoping I could get your opinion on and issue of mine. I have 2 full grown 4 year old tiger Oscars 10-11.5 inch , 1 14 inch zebra Pleco. in a 90 gallon aqua. What I was wondering , I was at the local pet store and was mentioned on buying a couple Jack Dempseys, so I bought 4 on the intentions that these fish were bread to grow a max of 6 inches in length. Is this true? < No, males can get up to a foot with females getting up to 8 inches.> Myself being from Edmonton Alberta Canada? < They will still get this big no matter where you are from.> Also as I was babbling on. < I noticed.> I have put all in the same tank ( the jacks are 1 inch ). With the jacks being small now I know they will be safe from the many many places to hide. Would I be able to contain this tank when they are full grown, even in taking in mind they would get bigger than 6 inch  and  living with two Oscars ? Cheers, T.E. < You are wasting you time. The Oscars will figure out a way to kill and eat the little jacks. They will not be able to hide for long.-Chuck>

Established Oscar Picking On New Fish  1/25/08 Hey I've had a tiger Oscar for about 4 months now. I got him when he was around 2 in which means he should be around 5 inches. But he's only 3 ½. I had him in a 10 gal for a couple months, which could have stunted him a little even though he was so small. I moved him and my 2 small upside-down catfish (Synodontis nigriventris) to a 30 gallon. (I know that's still too small but its not permanent). By the way I've barely ever seen him nip at the catfish, they get along great. I've had Oscars before that have all been very friendly and even have let me pet them, but this one is not as friendly. He's starting to get better about it, but slowly. He's just started taking food from my hand. Any suggestions on any of these things? < High nitrogenous waste levels can stunt fish. The nitrates should be under 20 ppm with 0 nitrites and ammonia.> Also recently I've decided to try to put another young Oscar in the tank with him. The first one was a 2 ½ in albino (1 in difference). That was a bad idea. The tiger that I already had beat him up pretty bad. I decided to return the small Oscar before he died and get a bigger one. Yesterday I came home with an albino that was about 1 cm bigger than the tiger that I already had. Before I put the new Oscar in I fed the tiger and rearranged the aquarium. They're getting along better but the old Oscar is still roughing up the new one pretty good. I don't think that the new Oscar has been eating. It's not like he's shy, he will drift to the top of the tank but seems to be too intimidated to eat the tiger Oscars food. Also the new albino Oscar has been chasing the upside-downs catfish around the aquarium when they come out. That kind of bothers me, is he just curious and will stop soon or is he going to keep going until he eats or kills them? Any ways is there anything or any food I can give the Oscars that will get them BOTH eating? < Oscars are very territorial and have established a pecking order with the catfish on the bottom of the list.> Also if it doesn't work out and I have to give the albino back what should I do? Should I try to get a bigger more aggressive Oscar, a more aggressive cichlid, or just leave the aquarium with the one Oscar? If I did decide to leave the Oscar as the only cichlid, could I get a Pleco, pictus, or a couple more upside-down catfish. What do you think the best plan is? PS- thanks a lot for answering any of these questions, it means a lot. < Here is how to do it for the long term. Start out with the tank that the adults will eventually be in. Buy small one inch fish and put them in all together at the same time. As they grow they will establish a pecking order. They are less likely to do damage in a big tank when they are little. The only thing you could do now is add dither fish like silver dollars, giant danios or rainbows.-Chuck>

Oscars: meals or tankmates, comp.    1/1/08 Hello there, How's everything going??? I have a quick question for you. I have always wanted an Oscar, no matter what kind but now I am afraid I can't get one because it is too aggressive or not I don't know. I have a community tank consisting of tetras, barbs, Plecos, Danios, platy, mollies, and swordtails, and an algae eater. I wanted to know if it was okay to put an Oscar in my tank. <Mmm, no...> I have a 50 gallon tank. Will my fishes get along? <They'll be terrorized, consumed in time> I will be raising the Oscar at 1-2 inches. Is there any way I can lower the aggressiveness of the Oscar? Also is my tank overstocked, after the Oscar, I am not getting any more fishes. Last, are Oscars aggressive I have read online sources and book sources saying they are extremely aggressive and when I read some of your FAQs, it said they are not that aggressive just a little territorial. Are they aggressive? Thanks so much for your time. And Happy New Years. <Best to have your Oscar/s in another system. Bob Fenner>

Oscar tankmate  10/25/07 Hello, I currently have a 6" Tiger Oscar and a 2.5" Convict, plus ~5 giant danios as dither fish in a 35gal tank. I have seen no aggressive tendencies in either fish. I will soon be upgrading to a 75gal with a 24" undergravel filter, an underwater filter (Fluval 4+), as well as either a canister filter rated for 100 gal or a fluidized bed filter also rated for 100 gal (still researching. My question is what other SA Cichlids can I add to this tank and how many, if any? I have consulted several books and consulted a large number of web resources, but have not found any consistency when it comes to Oscar tankmates. Salvini, Firemouth, and Acara are the ones I've seen most often and are on my short list. Jared <Jared, you're already WAY overstocked, so I wouldn't add any more fish. Adult Oscars need around 55 gallons simply because of their size. They aren't aggressive fish, but they are messy and need good water quality. In cramped spaces, Oscars are particularly prone to Hole-in-the-Head disease, among other things. As you hopefully know, wild Oscars feed primarily on shelled invertebrates such as snails and crayfish, but they do eat fish as well, and those giant Danios are definitely at risk of being eaten. For good health, adult Oscars shouldn't be fed daily -- but the problem here is that starving your Oscar for a day might well encourage it to eat the Danios! Once you've moved your Oscar to a large aquarium (75 gallons upwards) you might consider tankmates. Inactive, non-territorial armoured catfish are the classic companions (Plecs, Synodontis, Doradidae, etc.). Because Oscars are so docile, mixing them with other cichlids needs to be done carefully. I'd avoid Convicts and Salvini simply because of the risk of territorial aggression. At the very least, a mated pair of Central Americans will nip and harass even an adult Oscar to the point where Finrot and fungus become dangers. About the only cichlids I'd trust would be Severums, which also have similar water chemistry requirements. Festivums might be good, too, though they aren't as common in the trade as they once where. Since Severums and Festivums are largely herbivorous, there's not much competition for food, which helps. In fact the Oscars will benefit from getting a bit of plant material in their diet. But really, I'd avoid any cichlid companions. Simply much easier to work with midwater dither fish (such as Spanner barbs) plus some suitable catfish or loach. Cheers, Neale.>

Re: Tank height/width for Oscar (Neale?) 2nd part... Clown Loach comp.?  -- 9/27/07 Neale, Crew, As a P.S. Neale, I read the articles on the different Plecs, very good information. The only other fish I have a real desire for is the Clown Loach. I've never gotten any because my water is very hard (300 ppm) with a PH of 8 and everything I read says you 'need' soft water with a PH of 6 or so. I discussed my water with you recently in regards to the Oscar and you stated that seldom does a 'soft water fish' fail to acclimate to hard water. Would that hold true for the Clown Loach? Or is that stretching it too far? I know they can get up to 12" but it takes them many years to get there. I've also always read you 'have' to have a minimum of 3, do you agree with that? That would be what I'd really WANT to go into a 180 gal with the Oscar, I'm not sure my water would be acceptable though. I don't feel right "settling" for a Plec (although the Royal Plec is actually pretty) just to alleviate boredom. Thanks for helping me, I'm truly trying not to bother you! Mitzi <Clown loaches can and do thrive when kept with Oscars. Water chemistry is largely irrelevant with Clowns. What they appreciate it swimming space and water quality, both of which you're providing. When kept in groups of 4-6, Clowns become very different fish to how they seem when kept singly in a small aquarium. They scoot about nose-to-tail like Corydoras some of the time, though sometimes they'll turn around and snip at each other, perhaps establishing a pecking order. While they can get to 30 cm or so, that's uncommon in aquaria. A 15-20 cm specimen -- after 7 or 8 years of growth! -- would be pretty good going. Royal Plecs are very pretty, and I have one of my own. My favourite fish, and quite tame in her way. But so destructive of plants! Though she doesn't eat them, she uproots them, and causes me much grief in trying to make her aquarium pretty. This species mixes very well with Oscars. They are delicate after import though, so be sure and look for a nice, fat specimen with bright -- not sunken -- eyes. This actually holds true for all "rare" Plecs. PS. Usually, hard water fish have problems acclimating to soft water, and not the other way around. Soft water fish may not like hard water, but it rarely does them any harm. But when hard water fish are kept in soft water, you end up with fish that have fungus, finrot, etc. I think it's a question of soft water lacking essential minerals while soft water has a surfeit of them -- it's easier for soft water fish to adjust to excess, than for hard water fish to make do without entirely. There are exceptions, but few. Cheers, Neale> Re: Tank height/width for Oscar (Neale?) 2nd part -- 9/27/07 Oh good-thank you! The thought of actually being able to get some Clown Loach after wanting them so long makes my whole day :-)) They grow slower than I thought, I believe when the time comes I'll find 6 that are almost as big as the Oscar. He should still be under 6" by the time I get the 180 g so finding 5" Clown Loaches shouldn't be too hard. They'll definitely get quarantined also. I've wanted them for so long but didn't think I could have them without an RO unit. If it came down to it I could always get an RO unit in the future if I find they don't do well in harder water. Thank you! What great news for a Friday! Mitzi <Hi Mitzi. Clown loaches are definitely among the most slow growing fish in the hobby. In part, this might be because they're often kept in sub-optimal aquarium conditions. But they do also seem to be simply slow-growing, late-maturing, long-lived fish. Truly, hard water isn't an issue. These loaches are routinely kept by British aquarists, most of whom have to make do with "liquid rock". It's easy to fixate on soft water because it's more true to the natural ecology of many fish. But hard water has a key advantage: it's chemically stable. Fish will usually adapt fine to non-natural water chemistry, but what they HATE is fluctuating water chemistry. Unless you really need soft water, e.g., for breeding fish, then there's no practical advantages to using soft water with most standard aquarium fish. Cheers, Neale>

Re: Uaru tank mates (and my poor Oscar), Oscar Is A Bully -- 8/19/07 Thank you for replying so quickly, I think my best option is to invest in a new tank. Can you help me with one last thing (for now)? I have a 300 litre tank with two 4" Oscars, they are the only fish in the tank. One seems maybe half an inch larger and is a lot more aggressive, he attacks the smaller Oscar who now spends most of the time lying under an ornament. It is off its food somewhat and its colour is more a greeny with orange than the lovely black and orange it was a few weeks ago. It doesn't react to me either (which it used to) it seems very sad and lonely, is there any reason other than bullying for this or anything I can do to help? Thanks a million Chuck! < An Oscar is a cichlid and cichlids by nature are very territorial. With only two fish in the tank, they view each other as competition. So one will always be dominant in the tank and pick on the other fish. Way you can do is increase the number of fish and spread the aggression out. These other fish are called dither fish. Good choices would be silver dollars, giant danios or any other large, fast schooling fish.-Chuck>

Oscar with lobster, comp.    8/12/07 I'm hoping this email will go through at this address, I can't find the address to write to you but I see thousands of FAQ's on your sight where people have emailed you. My question... my 2" Oscar is going from his 40 gal tank into a 90 gal next week. I'm looking for a different or unusual tankmate. The blue cobalt lobster gets to 5" in a freshwater tank and is said to be non-aggressive to fish too big to eat. Do you think I'd have a problem putting a 2" blue cobalt lobster in with my 2" Oscar? I don't want my Oscar hurt but I also don't want to treat him to a $50 meal either, I'd like them to become tankmates. Is it a good idea? I've been reading your sight non-stop for 3 days and I love it! Thank you so much, Mitzi Potter Oklahoma <I do think this could work out splendidly... Do make sure there are plenty of rocky spaces for your Lobster to hide while it periodically molts (lest it be eaten by the Oscar then). Cheers, Bob Fenner>

Re: Oscar with lobster  8/13/07 I appreciate your answer more than you know, Bob. I've also researched the Blue Knight Lobster (a 2" one) to put in with my 2" Oscar. Said to get about 12", have smaller claws and seem not to chase fish because they're too slow to catch them. If that's actually the case I'd like to go with one of them instead based on your opinion My concern is whether a 90 gal is big enough for an adult Oscar and an adult Blue Knight Lobster (no other inhabitants). If you think 90 gal isn't enough, I'll go with the Blue Cobalt. <Is large enough for either combo.> One thing I've gathered about your sight is that you all will actually know whereas other places often don't. So while I hesitate to bother you again, I value your opinion. Mitzi Potter Oklahoma <No worries. Bob Fenner, who has kept a few species of Crayfish...>

Re: Oscar with lobster 2  8/13/07 Don't bother answering this message I sent earlier. I've decided I don't want a lobster as big as my Oscar (slow & small-clawed or not). That's just too big of a risk to my Oscar. Thanks for your time and have a great day! Mitzi Oklahoma <Okay... RMF>

Oscar with blue crayfish   8/18/07 I'd asked your advice last week about adding a 2" blue crayfish to the 90 gal tank I was moving my 2" Oscar into. You were quite helpful and said it should work nicely. I bought a 2" blue crayfish who's in quarantine right now. I asked the fish shop owner if the iodine (that crayfish need) would hurt the Oscar. She told me #1 that crayfish don't need iodine and #2 that yes-it would kill my Oscar. Ok....so now I'm thinking I don't really trust what the fish shop said because I do know crayfish need iodine (or am I wrong?) I've looked on your sight and can't find whether the iodine would hurt my Oscar or not. Could you tell me whether iodine would hurt my Oscar? Also, how much iodine does my crayfish need? I want to do this right but I'm having a heck of a time with getting the correct information from different fish shops. Your sight is truly the only one I trust. Thank you for your time, I know you're in high demand :-) Mitzi <Hello Mitzi. I'm going to disagree with whoever told you an Oscar and a crayfish will get on. They won't. Guess what Oscars mostly eat in the wild? Correct! Crayfish. Also crabs, shrimps, and snails. Basically anything with a shell. Contrary to popular belief, wild Oscars don't eat a lot of small fish. They are too slow to catch them. But their excellent eyesight and very strong jaws are perfect for finding and crushing shelled invertebrates. So, sooner or later, your Oscar will view a crayfish as food. (Of course, this also tells you another thing: the correct diet for Oscars is not based on fish, but on crustaceans and molluscs. But don't get me started on how unhealthy feeder fish are as a diet for Oscars!) Anyway, I have no idea why you need to add iodine to the aquarium. Crayfish are omnivores, leaning towards herbivores. In the wild they feed principally on decaying plant material and algae, supplementing that with carrion, i.e., the odd dead fish. A similar diet in the aquarium should give them all the nutrients they need. Using foods based on algae, such as Sushi Nori or algae wafers, should provide ample iodine. Giving your crayfish some marine invertebrates or fish, like krill or lancefish, once a week will provide the other minerals they need as well, such as calcium. What does matter is that the water is at least moderately hard and not acidic. Crayfish, like other shelled invertebrates, are more prone to problems in soft and acidic water. Bottom line, your crayfish needs its own ~10 gallon tank, where you can feed it plant material six days a week and a meaty treat on Sunday. Cheers, Neale.>

Re: Oscar with blue crayfish   8/19/07 Hi Neale. Bob Fenner is who said they'd be good tankmates (the crayfish gets to about 5" and they're both starting off at the same 2 size-too big for the Oscar to eat). They'll be in a 90 gal tank. And Sabrina (on your sight) is who has stated many many times that they need iodine, she has crayfish. With all due respect the crayfish gets far too big (in my opinion) for a 10 gal tank. My water is perfect for both crayfish & Oscars straight out of the tap (lucky me). So I'm back to square 1 it seems, aren't I? Not sure where to go from here aside from more research. Thank you for your time :-) Mitzi <Hello Mitzi. There's plenty of scientific research on rearing crayfish, since they're a valuable crop in many parts of the world. So finding out objective information about rearing these animals should be easy. I have absolutely no doubt about Oscars eating crayfish -- please visit Fishbase and you can read that yourself. It's the second item on their list of preferred prey! Obviously what matters is the size difference, if any. But the common species of crayfish sold as pets stay quite small, but Oscars get quite big, so sooner or later... The problem isn't so much day to day, but when the crayfish moults. When that happens, it has no defence, and the Oscar might decide to have a nibble. As for the size of the tank, that naturally depends on the species being kept. There are small crayfish and there are big crayfish. I cannot possibly know which one you have. But the small Astacus type things widely used as lab animals are fine in 10 gallon tanks. But a 20 cm Cherax quadricarinatus will obviously need something bigger. I have no idea why Sabrina reckons they need extra iodine. But I imagine the major problem experience by aquarists keeping crayfish may be dietary, and specifically problems with lack of green food. But crayfish are incredibly easy to look after, and in their own tanks are basically indestructible. Where people go wrong is the lack of greens and, in the case of coldwater species, too much heat. (A lot of the supposedly tropical species are actually subtropical or coldwater, so get the Latin name of your species to confirm this either way.) Bottom line, I'd consider mixing any fish with a crayfish a gamble at best, with both the fish and the crustacean running the risk of being attacked and/or eaten depending on the circumstances. Your move. Cheers, Neale> <<RMF is still of the opinion that (given cover for hiding during molts) that these species could co-habitate. Oh, and do need iodide>>

Re: Oscar with blue crayfish -- 8/19/07 Hello, Crew, Neale, you'd asked the Latin name for this crayfish, it's Procambarus sp. <Mmm, will send this along to Neale as well... Maybe Procambarus clarkii... the most common (of a few hundred) species of Crawfish in N. America... and the principal animal of human consumption by this name.> Bob, thanks. I'm of the opinion they'd be good tankmates in a 90 gal also. <Mmm, maybe not "good", but good-enough odds for a likely mix... I do agree with Neale re the penchant for most Astronotus to ingest such shellfish... but given the starting size of both, enough space and cover... I would give better than 50% odds of them getting along> The crayfish will have his choice of 8-10 rock caves and holes too small for the Oscar to get into for when he molts. I wanted some sort of 'living creature' in there with my Oscar so he wouldn't feel totally isolated. But not another fish he felt the need to compete with. I think a blue crayfish is a good choice and will go ahead with that. I guess it's a matter of getting opinions, weighing the pros and cons, making it safe for both then going ahead with what each person believes is a good move. Sounds too much like "life" to me <g>. Thanks all, Mitzi <Do please keep us informed re the ongoing... BobF>

Community Cichlid Tank Recommendations -- 07/01/07 I have emailed the crew before about tank advise about a community of cichlids. Could you please send me something in return about advise on a 75 gallon tank with some different combinations of cichlids. I have a particular interest in Oscars (veil tail) and parrots of any color. But please feel free to send me a combination of cichlids that can inhabit the tank as well as any advise you see fit. Thank you and thanks for replying so quickly last time. < Oscars are fairly aggressive and can get up to 12 inches long. Parrot cichlids are a hybrid and among the most peaceful of cichlids. They too can get up to about 12 inches over time. If you want an Oscar then get a few and let them grow up together. When they start to get around 6 to 8 inches they will start to become a bit feisty. In the end you may end up with one large Oscar after giving the others away. Parrot cichlids are fairly docile and you could probably keep six together to adulthood as long as the water was kept clean and you kept up on your water changes. I would recommend three chocolates cichlids, three severums, three jurupari a pleco and a few silver dollars if you wanted to stay with bigger fish. These fish are not very aggressive but have lots of color and personality.-Chuck>

Are my Oscars ok with my other fish? I have a few tanks set up at the minute, I've only been interested in aquariums about 2 years now (so I'm still learning). <Me too, though I've "had" tanks (or is it the other way around?) for decades> I've recently bought two tiger Oscars they are in a 90 litre tank they are only 2 inch's at the minute, I also have 2 Uaru fish in this tank, they too are just under 2 inch's, Are these fish ok together? <Mmm, no... in time the Oscars will work the Triangle Cichlids woe... Might not be as bad, as quickly if this system were much larger... but I would separate these and plan on having even a much larger system for the two species in a half year or so...> The Uaru are extremely timid and the Oscars usually stay in under ornaments when the lights are on. Is this normal? Many thanks Karen <Mmm, not really normal behavior for the Oscars... but they can be shy at times... Grow out of this in time, with training by you, feeding... Bob Fenner>

Gold Oscar and banded severums... Mis-mixed Cichlid "system"  5/17/07 . Hi guys... <Sujay> keep referring to your site whenever i have any trouble with my fish.... i must say that you guys do a really wonderful job and sometimes i just end up spending loads of time because its so interesting reading. <Me too!> Fortunately (touch wood) till now i haven't really ever had a problem so big that i needed to write in.... unfortunately, there is always a first time, i guess.... I recently got myself a 450 litre tank, (which i think would translate to approximately about a 100 gallons or more though i am not too sure of the conversion)... <Easy to do on the Net...> and have been procuring fish to fill the tank with... <I don't "like" the wording here... nor the implied philosophy> yesterday i got myself a "golden Oscar".... am not too sure of the species <All Oscars are the same species, Astronotus ocellatus, http://fishbase.sinica.edu.tw/Summary/speciesSummary.php?ID=3612&genusname=Astronotus&speciesname=ocellatus> since i have never seen one of these before, not even on the internet... its been about 24 hrs since i have him, and initially he was shy and hiding, but now he's quite active... he's about 7" long including fins and has started chasing the smaller tiger barbs in my tank... <These last will be consumed... these fishes are NOT compatible> as a matter of fact, 2 have gone missing since last night, but i could credit that to my other fish- 2 5" firemouths or the jaguar.... <...> he seems pretty active... sometimes he's shy, which i think is normal for Oscars, especially since he's new, but he swims about when he feels like and like i said he's started making a dash a the smaller fish... they're too fast for him but i don't know how his predatory habits are with the light out... the problem is that firstly, he hasn't eaten much since i have gotten him... maybe i shouldn't worry since he came in last evening only, but its been three meal times (!?!)... <Not to worry. Not atypical behavior for a newly introduced Cichlid> he comes up looks at the food and then wont eat....i feed them quite a variety- from flakes to blood worms to tetra vegetable  flakes as well as tetra bits and smaller pellets and stick food... usually mix them up and feed it to the fish- holistic diet.... but he doesn't want anything.... <Try worms of some size, insect larvae... eventually will eat all types of foods> today i noticed that he's picking up a sort of whitish film/ coating on the centre of the surface of his eyes... <Likely consequent from netting, moving... Do you have appreciable nitrogenous waste present?> the right side is worse than the left... he's got big froggy eyes and they show out against it... i did not notice this earlier (maybe cos i wasn't paying attention)... i don't know if this is related to his not eating... both of these are causing concern to me... please advise <Please read here: http://www.wetwebmedia.com/FWSubWebIndex/fwenvdisfaqs.htm and the linked files above> Along with the Oscar i have 2 banded severums as well... they came a day before him... they're always lying around and their colours keep changing depending on when you seem them... <You should now and get in the habit of reading re the issues of Compatibility and Systems for the livestock you have, and are considering purchasing... Likely the Severums and Firemouths will suffer from being mixed with the Jaguar and Oscar...> they range from grey to white and when they are white one can see redness on their bodies... the tank has a good number of plants <These also will go> and rocks and its not always easy to keep an eye on them.... but both the severums seem to be very shy.... <Is their nature> initially they were okay, hiding behind leaves... though sometimes they would suddenly swim the length of the entire tank... today though one of them has been lying on his side forever.... he came up when the food was "served" but i didn't really notice him eat anything... and he' gone back to lying on his side.... he doesn't breathe labouredly and once ina while when you see them swimming you think they are perfectly fine... am bit confused... i have 2 gold severums, and i am aware that these are generally shy fish, but i have never seen fish behave this way before.... its quite confusing and i don't know if there is reason to panic or not...!! please advise warm regards Sujay <I advise you to get/read a few books on Cichlid husbandry... And to investigate before buying... You've already set yourself up for trouble here. Bob Fenner> Re: gold Oscar and banded severums... Reading/using WWM   5/18/07 Hi Bob... <Sujay> thanks for the advice and the prompt response. <Welcome> I guess you are right regarding "mis-mixed cichlid system"... Have tried to read as much as i can before i bought/ buy my fish... most of it is off the net and i haven't yet found a very holistic and informed approach i can adopt... <The Net... isn't "quite there" re many topics as yet...> also, since its the first time i am keeping fish/ cichlids i want to observe and make judgments first-hand as much as possible... <A very hard way to learn... especially for your livestock> my jaguar is way smaller than the others, almost half the size of the severums and around a third of the size of the Oscars... honestly, the most aggressive fish i have in the tank right now are the firemouths and they haven't really attacked anyone as yet, though they do keep chasing the others once in a while... <Only a matter of time here> My Oscar has become quite active... initially i never really fancied these fish much but the more i notice him the more interesting he seems... the severums disturb no one and no one disturbs them... but one of them still keeps lying around all the time and the red rash on his side wont go... is this a normal coloration?!! <Mmm, no... is a stress response...> The red rash looks like clay off a tennis clay court which is smeared over one side of him... have never seen the other side honestly... The white on the Oscar's eye remains... its not grown anymore, but neither has it decreased... <Read on WWM re...> I am wondering whether i should medicate the fish with salt? Also, since i buy stuff from the pet store, i don't knew what the medication i buy contains... I buy this brand called "rid all"... i don't know if you guys use the same thing there... and you products called "general aid", "anti-ich", anti-anchor worm... but i don't know which of these are effective against either bacteria, fungus, protozoa or something specific like this... Please advise again warm regards.... Sujay <Please learn to/use the search tool, indices on WWM... There is too much to relate to you (in time) in this going back and forth fashion. BobF>

Tank Mates For An Oscar  - 03/20/07   Hi guys, I have a question regarding my 55g tank and my Oscar.  I keep getting mixed responses about getting a tank-mate for him or not.  Only reason I want to know now is because he is still very young (1.5 - 2 in.) and I would like him to get acquainted with an other.  Some websites say getting another cichlid and/or a bottom feeder would be fine and some say no way to either.  I'm going to go by your guys advice because it seems y'all are very educated in this matter =)   Thanks!! <Thanks for your kind words. If you do want more than one Oscar then get one ASAP so they can grow up together. An ideal situation would be to keep your Oscar alone, but if want to keep more than one together the sooner the better.-Chuck.>

Oscar comp.  3/10/07 <<Hey, Brian. Tom with you.>> I have 1, 1.5 inch Oscar 1, 1.5 inch Bala Shark And 1, 1.5 inch Pictus catfish in a 30 gallon tank, only temporary, of course. Could these fish have problems with each other if starting off so young and, how long do I have before the Oscar kills the others?     <<On its own, the Bala won't have a problem with either of the others. These fish mind their own business and will likely grow too quickly and large, not to mention fast, to be seen as a 'meal' by the Oscar. Territoriality might play a role here since the Bala Shark will be all over the tank and the Oscar could see this as a threat to its 'space' but given the immaturity of the fish right now, there's a good chance that the Oscar might choose to ignore this. The Pictus may become territorial as it matures, just as the Oscar will, but its protective spines, particularly in the dorsal fin, will make it a poor candidate for 'lunch' where the Oscar's concerned. As to the Oscar, specifically, much here will depend on you. Without guaranteeing the behavior of any individual fish, your Oscar may live peacefully with the other two with little or no aggression. Providing your Oscar with 'feeder fish' to munch on will increase its predatory/aggressive instincts as well as increasing the likelihood of a battle with its tank mates. As your post implies, a much larger tank would be in order and lessen the chances of disputes. The Oscar's 'reputation' notwithstanding, the Bala Shark can grow to be a foot long and will need lots of swimming room, which will make a larger tank very advisable here. Overall, Brian, I don't see any significant compatibility issues with the fish you have.>> Thanx,    Brian <<Any time, Brian. Tom>>

One of my Oscars is ill... terr.   - 02/21/07 We have a albino Oscar and two red tiger Oscars in a 75 gallon tank together. The 2 red tiger Oscars we have had for about 2 years now. They were bought together, and are always hanging out together. I believe they have been trying to mate for some time, but never lay eggs. <Mmm, might be that they're both male...> Recently though, the female red Oscar's skin on her head has been peeling off and leaving a pinkish, fleshy look to it. Also she lays on the bottom of the tank a lot, and has not had the greatest appetite. Just about every time one of the other Oscars gets near her she shakes her back fin at them (almost looks like it's vibrating). <This is a good clue... these fish are engaged in fighting... the one is losing...> She will do this even when she is laying almost sideways on the bottom of the tank. She does venture to the top sometimes, and will eat sometimes also. Do you have any suggestions as to what might be causing this? <Territoriality in a word> And any treatments you suggest. I am afraid she is going to die is this continues. Thank you for your time, Kelley Murry <Mmm, well, you're faced with basically two choices... to separate these two fish or to try "something else" to "take their minds off each other".... Like adding "ditherfish"... I would at least put a separator twixt them... Now. You can read re ditherfish on WWM, elsewhere. Bob Fenner>

My 3 Oscars aren't getting along...  1/26/07 I have 3 Oscars (1 Albino Tiger [4"], 1 Tiger [3.5"] and 1 Red [2"] all in a 47 gal. tank) <Trouble... not enough room, one too small...> and the albino (Whiteout) and the tiger (Butthead) are getting along but they keep leaving the red (Beavis) out of their activities. Whiteout and Butthead, I think, are a pair from what I have researched, they stick together and explore the tank daily hardly leaving the other's side. <Territorial animals... a 47 is too small...> Beavis is kind of a solitary guy and he tries to get along with the two but whenever he gets too close, the two take turns butting him in the side. Only when it comes to feeding do they get along and it's the better hunter who gets the feeders <A very poor idea... see WWM re> (which is usually Whiteout).  I want to know what to do with them and should I introduce another Oscar so that Beavis can have a mate?   <Mmm, no... need to remove the smallest fish... pronto... or it will be killed> I've read the other FAQ's on your site and I do not want Beavis to be stressed and so far he isn't showing signs of that yet. Thanks, Nicole <Another tank... eventually a much larger tank... Please read here: http://wetwebmedia.com/FWSubWebIndex/oscars.htm and the linked files above. Bob Fenner>

Oscars Acting Strange   12/17/06 I have had 2 Oscars for about a year. I got them both at the same time. One really took off and the other one grows slowly. They share the tank with a algae eater. Recently the larger one has been banging himself against the aquarium wall and swimming sideways. I have tested the water with normal results. I have taken water to pets smart and it was fine. I am not sure what else to do. He is starting to have some of his scales peel off as well. I truly need some help!!!!! < When you put two fish together in the same tank one always becomes dominant. This means one gets all the food and bullies the other around. The submissive fish tends to hide and stay out of the way so as not to get beat up. The larger Oscar now is seeing his reflection in the glass and thinks it is another fish challenging him for his territory. As he attempts to get the other fish he hits his head on the glass. swimming sideways is his way of showing how big he is and trying to intimidate the other fish. Try cooling the water  down to the mid 70's and see if that calms him down.-Chuck> Semper Beatus Jon M Carroll

Giant Red Finned Gourami... comp.   12/12/06 Hi there, <Hey there> I have a giant red finned gourami in my 100 gallon aquarium.  Since I've added him a year ago, he has grown at a fast rate. <Ah, yes... the "true" goramy (not a mis-spelling), Osphronemus> He is currently 13" from lip to tail.  The problem is, since he has grown he has become very aggressive towards a large albino Oscar. (around 9" long).  He is fine with the regular Oscar and Green Severum. <Need much more room... The albino is more similar to the Gourami in appearance> He just doesn't seem to like this Albino Oscar.. he behaviour has been getting worse recently, and he took out one of the eyes on the Albino. <!>   I don't have room in my apartment to separate them, what can I do to calm his aggression?  I've tried rearranging the aquarium, it works for a few hours at most. Thanks for your time, Justin <A much larger volume might help, but at this point, removing either the aggressor or the losing Albino is the route to go. Bob Fenner> Oscar Fish... health, comp.?   12/2/06 Hi, my name is Lindsy. <<Hello, Lindsy. Tom here.>> My husband and I have a Jack Dempsey, Albino Oscar and Plecostomus. My question is about our Albino Oscar. He is still a baby about 4-6 inches long. Well, his fins are shredded and one of his front fins is disintegrating. Also his scales are coming off, now large chucks of scales. I was watching him earlier and a large piece about an inch long was floating half on him and half off and I watching him rub himself against the gravel to remove it. At first we thought the splits in his fins were because he likes to hide in the plants and was at first thought our Jack Dempsey was getting territorial and going after him now that the Oscar is catching up in size. <<Plastic plants may cause this type of damage in fish with long, flowing fins like Bettas but doubtful, to me, that this is the root cause in the case of the Oscar. I would, however, concur with your thoughts on the Jack Dempsey and the Albino Oscar getting into territorial squabbles, particularly if the tank isn't really large and 'broken up' to provide them with specific areas to lay claim to.>> I do believe the two have gotten into it before but for a few days our Oscar wasn't eating. Today is the first time he's actually moved around and gotten his food. I am starting to think it's not the Jack that's hurting him and that something is wrong with him. I've tried to find answers online but haven't found anything useful. I just wanted to know if you might know what could be wrong. Thank you so much for your time and I hope my email isn't too confusing. <<Lindsy, the possible (probable?) order of events is that the Dempsey went after the Oscar, presumably over territory issues. The fins on the Oscar were damaged likely leading to a possible fungal infection which further led to a bacterial infection affecting the scales on this fish including their subsequent 'peeling away'. Whether, or not, the intermediate fungal infection has occurred, the real concern is the bacterial infection. Treatment is best accomplished in a separate hospital, or quarantine, tank. The reason for this is three-fold. First, we don't want to medicate the other fish, if it can be avoided, as this can be stressful and lead to problems we didn't have to start with. Second, antibiotics aren't discriminate about what they 'control' where bacteria are concerned. The 'good' nitrifying bacteria in the tank and filter are going to be killed, or inhibited, along with the 'bad' bacteria, leading to potential ammonia/nitrite spikes. (Don't buy into any 'garbage' about a particular antibiotic being harmless to your beneficial bacteria. By pure definition, this is total bunk!) Finally, there are antibiotics that shouldn't be used on 'scaleless' fish like your Pleco. Additionally (like you really wanted to hear more!), there are medications in this group (antibiotics) that are rendered 'inactive' in certain water conditions. The Tetracycline's, for instance, bind with calcium and magnesium -- found in 'hard water' conditions that many Cichlids are kept in -- making them ineffective. All that said, I'm going to recommend that you perform a water change in the range of 30%. Make sure to vacuum the substrate, if any. Clean your filter and remove any carbon media. If possible, isolate the Oscar from the Jack Dempsey even if it means purchasing a divider of some sort for the display tank. Treat with Nitrofurazone (Furanace) exactly according to the manufacturer's instructions. Watch the Oscar's condition closely. Not uncommon for bacterial infections to migrate to the internal organs which could entail treating with Metronidazole as well. Above all, monitor the water parameters and be prepared for spikes in both ammonia and nitrites. Increase aeration in the tank to keep oxygen levels up. (Be aware that Nitrofurazone is photo-sensitive and will decompose in the presence of light. Keep the tank darkened with a cover, if necessary, while treating your fish. The decomposed medication will not only be worthless as a treatment but can turn the water toxic.)>> Thanks, Lindsy <<Sorry for the whole 'song and dance', Lindsy, but otherwise well-meaning retailers might attempt to "steer" you. For example, Maracyn (erythromycin) is most effective against gram-positive bacteria which are the least probable statistically, by far, to be the source of the problem. Best that you go into this with as much information as possible. Best of luck to you. Tom>>

Oscar tankmates    11/29/06 I have a 75 gallon tank with one Nicaraguan cichlid, one blue Acara, and one cutteri.   I am moving my daughter's Oscar( about 8 inches ) to the 75 gallon tank. Can I keep all the fish in the tank or do I need to get rid of some of the fish.  If so, which ones to keep and which ones not.  My concern is with water quality. Thanks Larry <You are wise to consider this before moving this fish... It may well be that these fishes will get along... but I would keep an ever-vigilant eye on the larger species... particularly the Oscar amongst what you list. Water quality issues can be avoided by having sufficient filtration and doing weekly water changes (up to 25%) combined with gravel vacuuming. Bob Fenner>

Adding Fish To An Oscar Tank  - 11/13/06 Hi, I have to say this web site is the best that I have seen around to find good information on fish! < Thank you for your kind words.> I come here first before I look anywhere else.  I have a week and a half old new fish tank.  Although it may have been too early I went ahead and bought a Tiger Oscar(3 inches), a Firemouth Cichlid(2-3 inches), and a Green Terror(3 inches) to habit the tank.  I know that I should have waited a few weeks to even add any fish at all, but I'm past that point right now and the fish are doing well. I have been changing 1/3rd of the water out every 2 days, nitrites are at 0 still, and nitrates are under 20 or so.   I was thinking of adding another 4 inch Oscar to the tank but when I did my current Tiger Oscar started attacking the fish constantly. The poor new Oscar didn't even defend himself, I don't know if that was because he was just scared due to the move to a new tank, or if he just was not as aggressive as the one I have in the tank already.  I ended up bringing the 4 inch Oscar back to the store and returned him.  I don't want any fish to die.  Now my questions are, how long should I wait before adding another fish to the tank?  And should I have gotten my Oscar as the last fish in the tank?  I would like to add a blood parrot but I really don't want to have a $25 fish get killed as soon as he is introduced into the tank.   thank you in advance for the help. Kenny <Cichlids are very territorial. When you add a new fish it is seen as a threat to the existing fish's territory. They defend their space against all comers. The new fish is stressed from the move and unable to defend himself. Next time take out all the rocks and plants, do a 50% water change, vacuum the gravel and clean the filter. Replace the rocks and plants in different places. Add the new fish and then turn out the lights for the night. In the morning the fish will be establishing  their territories and the new fish will have a chance to get into the pecking order since all the fish will be after each other now. Do this over the weekend when you will be around to watch the fish. Don't do this and then leave for work or school. You won't be around to save the new fish from getting beat up.-Chuck>

Oscars Not Getting Along   9/6/06 My son and daughter-in-law got my husband and I for our anniversary an aquarium with two Oscars and two silver dollar fish. That was in May.  The male Oscar seems to be losing his scales and the female Oscar is attacking him.  His breathing seems labored at times. I don't know what to do. Up until now they seemed great.  They get fed cichlid sticks.  He doesn't seem to eat as much.  I think he's the male, she keeps attacking him, it's like she knows that there is something wrong with him.  Any suggestions? Debra < As long as he is in there with her he will not get better. I would recommend putting him in a hospital tank. Get him to eat and treat his wounds with Melafix. If he gets infected then switch to antibiotics like Nitrofurazone or Kanamycin. After he is cured and eating you will probably not be able to reintroduce him back into the tank. Oscars are cichlids that are very territorial. They see other cichlids as potential mates or as completion for food. Doesn't sound like they are going to mate. get another tank or find a new home for him.-Chuck>

Oscar With A Mouth Full Of Fish   8/29/06 Well, it is definitely time to get the dither fish out of my Oscar  tank.  My beautiful tiger Oscar is swimming around with a tail fin sticking  out of his mouth.  It is a Buenos Aries Tetra.  The Oscar is approx. 5  inches long at this point.  He appears to be having trouble swallowing his  chosen meal.   Should I try to assist in anyway, or will time take care of  the problem? thanks for any help you can give me, Gloria < Oscars can sure be little pigs. If he is trying to expel it then he is not confident that he can eat it. The spines on a characin aren't particularly stiff. If he cannot eat it and he is having trouble breathing then I would attempt to pull it back out. I would use a good pair of needle nosed pliers and slowly try to pull the tetra back out.-Chuck>

Re: Oscar with A Mouthful Of Fish II  8/29/06 I watched him carefully and after a few crunches (poor tetra), and some   patience on my part, he appears to have finished the task.  The other  dither fish will be removed and he won't be getting fed for a few days. Little pig is right! thanks, Gloria < Glad to hear he was able to finish the job.-Chuck>

Adding An Oscar To An  Established Tank  6/3/06 I just recently started my 55 gal tank back up, I currently have it stocked with a Columbian shark, a bala shark, one angel, and an Opaline Gourami, and a Pleco. I am thinking of adding an Oscar to the mix, will this be safe for as long as they are all the same size, they could be split up to another tank later if need be. Thanks in advance < An Oscar will not be able to catch or harm the bala or Colombian shark. It will destroy the angel and wipeout the Gourami in no time. Keep in mind that the sharks will get big.-Chuck>

Re: Adding An Oscar   6/9/06 Ok. I now have the tank split up and cut down to the Bala shark, a pleco and an angelicus, this should be ok right? Thanks in advance < This is better and the fish will last longer. When they get about 6 to 8 inches you will probably need to start shopping for a new and hopefully much bigger tank.-Chuck>

Older Oscar Not Defending Himself Hello, my name is Liv. I have had a 215 gal. Oscar tank for about 2 years. I have 2 lrg. filters w/ bio wheels, 1 300 canister filter, do 25% water changes weekly and keep the temp. @ 80. I had 7 Oscars, 2 bala sharks, and 2 lrg. Plecos but started having trouble with hole in the head. I tried medications and vitamins in their food but it only seemed to make it worse. They are fed pellets, blood worms, brine shrimp, krill, sliver sides, and algae wafers every 2-3 days. I now have sold all but 2 lrg. Oscars (15 inches), 1 med (9 inches.), 1 sm. (6 inches), 2 bala sharks, and 1 lrg. Pleco in the hopes that this would improve their condition but now I seem to have a different problem. I biggest fish in the tank (the red tiger) was always the dominant fish but now he being attacked by all the other fish (in particular the 8inch white tiger). I thought it may be a breeding thing so I moved a few things around and decreased the temp. to 76. This has helped some but has not fully corrected the problem. I can only turn the light on, on one side of the tank or they will start fighting again, they act lethargic, and only eat about 1/4 of what they normally did. What is going on? Any information would be helpful! Thanks Liv   < The larger fish may be ill and not up to defending himself against the younger healthier smaller fish. Try treating with Metronidazole for the hole in the head. It would be less expensive in a smaller hospital tank.-Chuck> Mixing an Oscar with Cichlids   3/16/06 I was wondering if I could put cichlids in the same tank as the Oscar without having the Oscar eating or fighting the cichlids? < An Oscar is a cichlid. Oscars can go together with some South American cichlids if they are all the same size and there is enough room for them to establish territories. African rift lake cichlids are much too fast and most are well  armed with sharp teeth that can tear into another fish pretty severely.-Chuck>

Oscar, new and with Africans   3/10/06 I've had my little Oscar for about 2 days now and ever sense I put him in the tank he has mostly just sat at the bottom leaning towards   one side. <Takes about a week to get situated> Occasionally he will jump up and do a quick swim after you scare him with the magnate scrubber.  He won't eat anything.  In the    tank there are to other cichlids one small yellow lab <Not a good idea to mix Great Lakes African Cichlids with Neotropicals> and a little blue fish with black stripes but they don't bother Oscar at all.  The tank is a 55 gallon. I think my fish may be sick. Are all Oscars this lazy or is mine just dying? <Neither... is new and likely frightened. Bob Fenner>

Oscar Tankmates   2/23/06 Hi.  I have a 70-gallon tank, and am deciding what fish to put in it. One setup I'm considering would be an Oscar with a Jack Dempsey, and I'd plan on adding the Jack later (and smaller).  Knowing that there's always a chance that any two fish won't get along, what do you generally think of these two in a 70G-enough room for each to establish a territory? < Each One gets to be pretty big and push will come to shove and one fish will get injured in a fight and need to be removed. A large scared up fish is difficult to find a home for.> The other setup I'm considering is an Oscar and a schooling fish-I think that would make a nice contrast.  With appropriate filtration and water changes, how many silver dollars do you think I could add? < They are schooling fish and need to be in a group of at least six.> There would be no other fish added to the tank other than the Oscar and the silver dollars.   Also please advise on any other schooling fish that I might consider.  I've heard both good and bad about Bala sharks with Oscars; and Tinfoil Barbs are also being considered, however I do think the Silver Dollars would make a more impressive display.  Thank you, Katie < Bala sharks get to be very large and pretty easily scared. Tinfoil barbs get very big too but are not as flighty.-Chuck>

Oscar Tankmates   2/24/06 Thanks, Chuck.  Am I understanding you that 1 Oscar and a school of 6 silver dollars would be an acceptable stocking scheme for my 70-gallon? < When everything is full size you are going to have to work to keep up the water quality. The filter should be pumping at least 300GPH and you will need to 30% water changes to keep the nitrates under control. Less fish means less work. Silver dollars are very active fish with high metabolisms. Less than six fish means they will be stressed.-Chuck>

Oscars Fighting   2/6/06 Hi, I have two Oscars.  I have had them about a month  now.  Everything is going fine but I did my normal water change and I have  noticed one of my Oscars hiding.  It started doing so because there is  dominance going on but yesterday I noticed his scales turning white.  It  looks like they are being scraped off.  My daughter said she has seen it  rubbing on the rocks. It does eat when I put food in the tank.  When the  other Oscar swims by he cowards down by swimming sideways.  He hides a lot,  But now he just hangs at the bottom and leans against the sides of the  tank.  He has a split in his tail fin and his other fins are the same  way.  I don't want to lose him.  Just not swimming around like he  did. Thanks, Barbara Wells < When you only keep two cichlids together there will be a struggle for dominance. While the winner is out and about, the loser will be hiding and trying not to get beat up. There are a few things you can try and do. Move everything around to  new locations. Lower the water temp to the mid 70s. Add other fast moving schooling fish like giant danios or rainbows to distract the dominant fish. Keep the water clean to prevent infection from the injured fish. Add Bio-Coat from Marineland to help the fish grow back its scales.-Chuck> Oscar Buddy   1/31/06 Hi!  I've been looking on Google and wetwebmedia, but I haven't found my exact questions yet (unless I have just overlooked it).  I have 1 albino Oscar, 1 tiger Oscar and a pleco together in a 30 gallon planted tank (lots of tank cleaning is going on, but they don't seem to mess with the plants)!  The tiger is about 6" long, the albino is almost an inch shorter and the pleco is about 8" long. <First off....this is way TOO SMALL of an aquarium to house these potential 14" fish!!!> They seem happy, healthy and get along great and we'll be moving them into a 75 gallon tank in the next week or two.<75 gallon is also too small. I would recommend at least a 72" aquarium..>  I've read elsewhere that the pleco may start to feed off of the Oscars instead of the rocks and side of the tank when it gets bigger. <most likely he will> Is this true?  Should I try a different type of fish? <no> I don't really need an algae eater, and love Corydoras, but is there a type of Corydoras which gets large enough to be safely housed with Oscar?<wouldn't trust anything small or non aggressive with an Oscar> I also "rescued" a tiny little Oscar who was in a Wal-Mart tank with a bunch of larger Oscars who were beating up on him.  He (or she) is only about 1 1/2" long and is currently in my small 5 gallon tank.  We will have a 55 gallon tank for him in the next week or two as well.  I am planning on putting a pleco in with the little guy as well.<good>  I was wondering if a single blood parrot would get along ok with the single Oscar and pleco in a 55 gallon tank? <i have tried this before and the Oscar will quickly outgrow him and bully him to death>I would be able to upgrade to a larger tank if need be, but wasn't sure if this mixture would even be compatible? <you can try it but the odds are against you> I had briefly considered letting the little Oscar get bigger and then put it in with the other two Oscars, but after reading some articles on your website, I've decided against this.<agreed> I don't really want him to be by himself though.  I've read from some that an Oscar can be perfectly happy by themselves and then I've read from others that they are not.  I don't really know either way!  What would you suggest?  <he should be fine by himself or with another small Oscar or pleco, good luck with these messy eaters!!, IanB> Thanks again!  (If my questions are answered already on your site, then I do apologize for overlooking them!) Patricia Oscar Tried To Eat Cory Cat   1/14/06 Hi, I've had my Oscars for about 4 months, the tiger is about 2 inches and the albino about 6 inches.  There were also to albino bronze catfish in the tank, the Oscars didn't bother these until now.  I arrived home from work today to find one of the catfish stuck in albino's mouth, my dad arrived and informed me that it had been there for most of the day.  I netted the Oscar and carefully tried to remove the fish, eventually in came out.  The Oscars mouth is now very open and I am worried as it is not feeding.  Do you think that my Oscar may die from the trauma, and should I take it to a vet, thanks for your time,   Alex < The protective spines of the Corydoras catfish work just as well in the aquarium as they do in the wild. If the spines broke off in your Oscar's mouth then you are in trouble. If you got the spines out then I would keep the water clean and treat with an antibiotic for infection. Your Oscar can go for more than a week without food. Give it a chance to heal and remove all the smaller fish that can be considered food by the Oscars.-Chuck>

Oscar Basking In the Moonlight was: Oscar Tried To Eat Cory Cat   1/22/06 Thanks for your help, he is back eating properly again now, his mouth has closed up although it is slightly off centre, other than that he is fine. I have been toying with the idea of getting a moonlight effect bulb for my tank, will this confuse the fish and make them think its night time all the time, or will they be okay with it??    Thanks again for your time,   Alex < Oscars are pretty smart and will be able to tell the daytime from the night time from the ambient room light. I do' think you will be able to appreciate your Oscar too much under those lighting conditions.-Chuck>

Adding a Tilapia butikoferi with Oscars  12/16/05 Just a couple of things really. Firstly, great site and keep up the good work! < Thanks> Could you please tell me what the hell a Tilapia butikoferi is and find me a picture and/or any information on it as it's not on Fishbase.org nor can I find it anywhere else using Google etc. < It is a large African Riverine cichlid. Try Tilapia Butikoferi on your next search. They get pretty big but have a great vertical black and white striping that stay with them even as adults.> Just a quick note now on my tank and pets therein. I have 2 Tiger Oscars (Lemmy & Hendrix) and 1 Tiger Shovelnose Catfish (Violet). Do you think this is a good mix? < The tilapia gets bigger and meaner that the Oscars. As long as they are all the same size then they might get along. The tilapia will dominate the tank.> At first the Tigers (Oscars) seemed a little apprehensive and sulked with me for adding a tank mate but now they all cuddle up on a night and swim fine during the day. At current my tanks only a 36"x18"x15" but they're getting a 4 footer next week and I'm moving around September next year so they'll be getting a 5-6 footer then so they should be alright for now. As long as I keep up to my water changes and (hand) feed them all they're happy. I'll try and get some pictures on sometime. Thanks again, Pete < Many books say that the tilapia butikoferi only gets to about 10 inches, but I have personally seen some in the Midwest close to 18 inches. A big mean fish is hard to get rid of.-Chuck> Bigger Oscar Has Become a Bully 10/22/05 The website seems much more organized since the last time I visited. Thank you! Much easier to find information without wading through pages of emails... Now, I need some advice on a tiger Oscar. Let me start by saying that I've had two tigers since they were the size of half dollars, and they are the newest additions to the tank. They live in a 75 gallon tank, with a four-inch armored catfish and an 8" Pleco. The Oscars are both slightly over 6". I run two 60 gallon Whisper filters and do a 25% water change every 7-10 days. They eat everything to Cichlid pellets to worms, crickets, and chicken. < Chicken?> <<Land mammal and poultry meats should never be offered as food to fish, with the exception of beef heart only in certain extreme cases.  -SCF>> For the last couple of months, the two tigers have been lip locking and pushing one another around the tank. There are no sharp edges, and neither of them get beat up (minus a scale or two I find vacuuming). For the last week, the seemingly dominant tiger, has been bullying around the other roommates as well. Surprisingly, it has even been going after the Pleco, which has always been larger than itself.  Now, when I clean the tank, it is charging and biting me, as well as the vacuum, plants, and even water drippings from the carbon filters as I pull them over the top of the tank.  Although I find this slightly amusing and no one is getting physically hurt, I am beginning to be concerned for the psychological well being of the other tank mates. Should I move that Oscar to a tank of its own? < Your Oscar has now determined that this tank is his territory and that he is in charge. He will defend his territory against all intruders.> Will it become lonely? < No , he will start interacting with people walking by the tank or even in the same room.> Can this behavior be from diet related issues? or perhaps the vacation that I went on when I didn't change the water for 13 days? < This is actually pretty normal for every large New World cichlid.> Also, I've been thinking about buying a separation screen for the catfish so that it can eat without the Oscars snatching up everything. How long should I give it to eat before removing the screen? < Most fish I recommend leaving the food in for no more than two minutes. But with the Pleco I would make sure that he is eating for about 15 minutes each day. Vegetable fish food is high in fiber and not much protein, so they need to eat a lot of it to get enough nutrition.> It will not eat pelleted food for catfishes or anything that floats. I'm concerned that I'm not providing a wide enough arrangement of food with chicken, earthworms, and blood worms. Any suggestions? Beef doesn't seem to work in any form: hamburger, steak, or heart.  Thank you very much for your time, Chris < Go with commercially prepared sinking pellets for algae eating fish and stay away from the grocery store. Try Spectrum, Hikari, OSI or Marineland pellets. You fish will learn to eat them after a few tries.-Chuck> 

Angry Oscar Needs His Space 10/22/05 Thank you for the timely response to my last email. Should I make a new tank for the aggressive Oscar? <This would be best for all of your fish.-Chuck> 

Oscar compatibility 9/23/05 Hey again, everything is going well with my two babies eating now, but one is a hair larger than the other and he wants to ram the other all the time, tries to keep (her, not sure) from eating, and now she is scared and shy, any suggestions? J >> Oscars are not fish that do well in pairs, you will either have to grow out a group or keep one single animal. The smaller fish will always be dominated and will stop growing, and may eventually get killed. It may be best to separate your two Oscars now. Good Luck, Oliver

Oscars with Frontosas  9/20/05 I'd like to first say how much help your site has been toward the raising of my Oscars.  I have a pair of very young tiger Oscars who will soon be moving into a gorgeous 135 gallon tank.  Right now they are living very peacefully together with a Plecostomus and a small tiger shovelnose catfish.  I am very interested in buying a pair of Frontosa to go with them and I just want to know how compatible the whole set up will be.  I am not really interested in breeding the frontosa so I opted for getting a pair of males, but I was told by a local store that two males would fight and that it was not a good idea to house them with my Oscars.  I don't want to spend $500 on a whole breeding colony, which seems to be how everyone wants to sell them.  Any advice you can give would be greatly appreciated.  Thanks for your help guys. < As a general rule it is not a good idea to mix cichlids from different continents for a long time. I am sure it has been done by aquarists who want big fish and mix and match anything and everything. Big cichlids tend to get territorial and Frontosas and Oscars just don't speak the same body language. One will become dominant and bully the other around. The weaker fish will hide in the corner and become a poor display.-Chuck> Oscar Tankmates  9/17/05 Is there any chance their behavior has anything to do with, their tankmates?  They reside with about 20 other fish (Danio's, tetras 2-3" each).   < Not very likely.-Chuck> <<  Oscar Behavior   I recently purchased two tigers, both about 2 to 3 inches.  They currently share an 80 gallon tank with community fish ( I figured they would eat them when they got big enough and have the tank to themselves)  In the last two days my Oscars have been laying at the bottom of the tank.  They come up to eat (bloodworms, beef heart)  The other fish in the tank don't pester the Oscars, they show no visible signs of parasites.  I spoke to a person at the pet store where I purchased the Oscars and she suggested putting Parasite Clear tablets in the tank, which I did yesterday.   <... I would hold off on doing this... or adding any medication to your main tank>     Today I did a 25% water change (per the Parasite Clear instructions)  I have had the Oscars for about two weeks and this is the second water change.  I changed my filter, and my water levels are good.  This is new behavior for these Oscars, any suggestions?   <Try some other foods>   A footnote:  Prior to the community fish (Danios, tetras) I had a Tiger Oscar for about three years who died of hole in the head, about four months ago.   <Due to? Water quality, lack of proper nutrition?>   Thanks,   Sean   <Please read on WWM re Oscars, behavior. Bob Fenner> >> Sick Oscar with Silver Dollars 7/28/05 I have heard that Tiger Oscars and Silver Dollars can be in the same tank.  Is this ok, and if so, how many of them would you recommend? < Oscars and silver dollars get big. One Oscar and a few silver dollars would be plenty with proper filtration.> If this Oscar does not make it, I would like to buy another one, but a little bit bigger than the one I already have.  PetSmart sells them in 2 sizes.  Considering how big they get and the size of my tank (55 gal.), I think I will settle on 1 Tiger Oscar and a few Silver Dollars if it is safe.  What do you think? < Your Oscar is primarily a carnivore while the silver dollars are herbivores. So you will have to mix up their diet to keep them healthy but this should not be a problem. Stay away from the shrimp or worm only diets. Give them something a little more balanced.> I tested my water yesterday and all levels are good.  Nitrate is at the safe level, Nitrite color stayed white, and I have an Ammonia Alert wheel inside of my water that is safe as well.  I will treat with Melafix for 3 days and do water changes in between and hope this brings Tiger around.  Thanks. < I would be interested to see if your Oscar recovers with the MelaFix.-Chuck> Oscar Mix 7.24.05 I'm setting up a new 135, and plan to stock it with 7 Metynnis hypsauchen and three Pimelodus pictus. Do you think a single Oscar would be a reasonable addition? If so, I'm assuming that I would want to add it 1) small and 2) last; is that right? If it spends 4 weeks in the Q-tank, is it still going to be small enough to add without undue problems? How big should the other guys be before I undertake this (if at all)? <I'd feel ok about an Oscar in this mix, 135gallons should be enough room.  Just make sure no one is small enough to fit in anyone else's mouth, mainly the Oscar's.  After 4 weeks of quarantine he will still be small enough to add to the mix.  Gage> <<RMF would not place a pictus catfish and Oscar in the same system>>

Oscar Problems 7/9/05 I have a 75 gallon tank. When I first got it, I moved my 3 1/2" Tiger Oscar to it as the sole occupant. I wanted to get him a tankmate so I added an Albino Tiger Oscar that was about 1/4" longer than the first Oscar. My problem is that they don't get along. The smaller Oscar chases and attacks the larger Oscar, and is biting it's fins, and the larger Oscar just takes it and does nothing about it. They have been together for only about 3 days now, but I'm worried. I don't have anywhere else to put the albino if they continue to fight, and I don't know if Petsmart will take it back. Just so you know, I just tested the water and the Ammonia is at zero, NO2 is at zero, NO3 is usually at <25ppm, but today it was at <40ppm, Hardness (GH) is at 150ppm, Alkalinity (KH) is at 300 ppm, and the pH is at around 8.0. I know water changes and good filtration take care of ammonia, nitrite and nitrate, but what can I do about the Hardness, alkalinity, and pH? < Don't worry about it. These Oscars have been raised in hard water and they can handle it.> I am against adding unnecessary chemicals to the tank to change these things because adding stuff only adds to the osmotic pressure making it harder for my fish to "breathe", and my water is naturally this hard and basic. I don't have any kind of rocks or wood in the tank, not even gravel, I just have a few plastic plants and a fake piece of driftwood and a fake rock cave. Also, a larger tank is NOT an option. I just spent all of my money on this tank, and if this doesn't cut it I am likely just giving up, so don't even mention the tank being to small. < Two Oscars in a 75 gallon tank should be fine as long as they get along. Move the decorations around to break up any established territories. Add some dither fish like giant danios or large rainbow fish to give the mean fish some other fish to chase. you could always get a tank divider and separate them for awhile. Then try and reintroduce them later.-Chuck>

Oscar Tankmates I have an aggressive Oscar (actually two of them that I had to separate) that is alone.  The larger of the two is not the aggressor, rather the medium one is.  However, the large one wins the fight.  I have now housed the large one with a pink convict (the really mean nasty ones) and they seem to be ok.  I need to house the other Oscar with something but I don't know what is compatible with: 1.  A firemouth 2.  A pair of pink convicts (breeding) but not as aggressive as the one I had to remove. 3.  An assortment of African cichlids 4.  Albino Sharks Are these really rare like the article says?  I have one of these. Don't worry, I have about 20 different fish tanks.  I just want to know what I should choose from.  Every site gives conflicting information. For instance, they say to house an Oscar with a convict.  My convict are very very mean and my friends say the convict will kill everything. Please help. Rochelle Magness < Of all the choices you have offered I would probably go with the assorted African tank. One is the Africans are pretty fast and active so the Oscar will have a difficult time getting them and will soon give up after awhile.-Chuck>

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Oscar Tank Mates and Outside Ponds Ok.  But I like my Oscars.  How big of tank do I need for the two smaller ones? < If the two smaller Oscars are compatible a 60 to 75 gallon tank is needed.> The one that went berserk can't be put with anything, so I may just "put him to sleep".  I love my pacu.  Can they survive in an 80 gal or 100 gal? < For a while but they may get up to three feet long.> If I put nothing in it but them, a filter, and a heater? < Sounds boring but will work with lots of water changes when he gets bigger.> Obviously it will have to be an acrylic tank.  But I think I could swing 100 gal tank. As for the fish store comment - I already went in and yelled at Petsmart. Told them they were a family store that mostly sold to children and adults that don't know a lot about fish.  I mentioned that unless they were willing to train their employees about fish care and actually SELL a tank that could house any species they had, they should stop selling it.  At Petsmart, they don't carry tanks above 100 gallons and I told them they should not SELL any fish that can't live in a tank less than that.  I noticed that the last 3 times I went in (over a 4 week period) that they no longer carry Pacu.  At least it's a step in the right direction.  Told them to leave those fish to Capitol Aquarium where the employees point out what you need at the get go and they sell the equipment needed to maintain them. Note:  I don't believe in releasing the pacu or Oscars unless I am going to put them in the Amazon River.  They don't belong in North American waters. I can't think of anyone that would be that stupid after the Lake Davis thing.  You don't have to worry about me doing something like that.  Only an idiot would do something like that.  Just wanted to set the record straight. < Well said!!!!-Chuck>

How Many Oscars? Hi, I have a three foot long tank and wanted to keep two pairs of Oscar. Is it ok to keep 2 pairs? < NO!!!!! Each pair of Oscars should have at least a 50 to 75 gallon tank to themselves.> Is it true that they fight in small numbers and are better in large number ? <When fish are kept crowded a aggressive fish will have more fish to pick on a the aggression is diluted. If there is just on other fish then it is picked on all the time and soon will be dead.> How many Oscars do you suggest? < Only one.-Chuck>

My Oscar needs Help!! Hi, <Hello there> I was searching on the internet and found your site....I hope you can help me!!?? <Will try> I have an Oscar, along with 2 other Cichlids.  Recently, the Oscar has been bullied by the larger of the 2 other Cichlids...I believe they are Texas Cichlids (?)  I have attached photos of my Oscar's injuries.  He has missing scales from scraping the stones...those do seem to heal rather quickly...but I am mostly concerned about the red pimple-like bump on his lip (he's had for over a month) and the large superficial gash above his right eye, which I believe he got by jumping up and hitting the tank lid....he likes to jump and has even jumped form the tank before!!!  I am in the process of getting a larger tank to help with the territory issue which may be causing the aggression, however, should I be concerned about his wounds???  And if so, what can I do???  I do change the water about 30% every 1 to 2 weeks along with the gravel...I would appreciate any advice you can give!!!  I am really worried about his health and recovery. Thanks so much!!! <You need to separate the Oscar ASAP... the aggression is the root cause of the problem/s here... treating the injuries for it is futile. Please see here: http://www.wetwebmedia.com/FWSubWebIndex/oscars.htm the above linked files re Oscar Behavior, Compatibility, Systems, Disease. Bob Fenner>

Oscar Compatibility Hi I just recently purchased two tiger Oscars which are about 2-1/2 inches long. Well the past couple of days they have been hanging out in the top corner of the tank and not really eating. They also wont close their mouths and they both have what appears to be white poop hanging out. I have a 55 gal tank, just did a 50% water change last week and put my convict in the tank with the Oscars.( the convict is doing fine and eating normally). I also notice that they were starting to get ick so I put some Mardel Coppersafe in the tank about one week ago. Thanks for the help in advance Pete >>>Hi Pete, You CANNOT keep Oscars in the same tank with convicts - period. I've seen half grown convicts stress adult 12" Oscars out to the point where the Oscars were just laying on the bottom of the tank, pale and not eating a thing. Only when the convict was removed did they return to normal. So, fix this situation - your Oscars will thank you! Jim<<< Oscar scars!! Hello Bob (or who ever is reading this) thanks for helping people with their fishes at home. Anyway I got a 625 gallon tank and its stock.. 1.oscar 1.red devil 1. breeding pair of Flowerhorns 3.plecos 2.parrots 3.Jack Dempsey's 5.pacus 2 pairs of breeding convicts 2.red terrors Anyway I used to have 2 Oscars were both 6in but then the red terrors came and gang up on one of my Oscars and make so many scars that he died the next morning. Now they strike again but this time my Oscar lived!!! But I put the two red terrors in a 100 gallon I was not using. Can you help with my Oscar problem to never happen again???? Thanks Sean <Just keep more aggressive fishes, livestock out of their system. Bob Fenner> 

Convict with an Oscar? Hey, About a year ago, my hubby and I bought a breeding pair of convict cichlids.  They were very shy and would wait until I left the area near the tank to eat.  About three weeks ago, the female died (no known cause) and the male seemed rather depressed.  (By the way, the female was 1.5in and the male is 3.5in) I decided it was time to get him a tank buddy and picked out a 2in long Oscar.  I removed my convict, all the plants, did a 15% water change, cleaned the rocks and moved all the plants and rocks around the tank.  I placed the Oscar (in his pet store bag) in the tank and let him get used to everything for about an hour before releasing him.  Then about 30min later, I put my convict back in the tank.  I forgot to mention that this is a 55 gal tank with the works on filters.  The convict has totally taken over, but hasn't bitten, rammed or tried to kill the Oscar.  Was it a good idea to mix these two? Thanks, Becca >>>Hi Becca, Not only is a 2 inch Oscar an unsuitable tankmate for a convict, but I've seen 14" Oscars victimized by convicts no larger than 2"! The Oscar will sulk on the bottom of the tank, pale - and will not eat. This is a LARGE Oscar mind you, a smaller Oscar like yours will often be killed. Remove the Oscar and look to other medium sized, more aggressive Central American Cichlids. Regards Jim<<<

FW Ray and Red tiger, albino Oscar Hi, Can Ocellate River Stingray be in the same tank with an albino or red Oscar fish?  If not are there any other rays that can be in a tank with Oscars? <Possibly. Please read here: http://www.wetwebmedia.com/FWSubWebIndex/fwstingrays.htm  and the linked files at top> And if I get plants for my tank with Oscar fish will the plant get damaged if there is a rock covering the base so it cant dig it up? Thanks <Possibly... Large Oscars will pull up, destroy most types of live plants... there may be some varieties that are tough, fibrous that you can plant in clay pots... put some larger gravel, rock on top of that might last... Otherwise there are some very nice faux plants nowadays... Bob Fenner>

Oscar Questions I looked through your questions and didn't find quite what I was looking for so I thought I would email you, sorry if you have answered this before. we had purchased a couple of Oscars that both came from the same tank in the store and get along well in our tank. We just bought another one and introduced him. Our albino Oscar seems to like the new one but our black tiger Oscar doesn't, and seems to pick on him. and this has caused our first 2 Oscars to sort of argue.  Is there anything we could do to stop the bickering? If so, what? Thank you so much for your time. Lacie Anderson <Please read here: http://www.wetwebmedia.com/FWSubWebIndex/oscars.htm  and the linked files above... You don't state the size of the fish, the tank... but Oscars are smart and persnickety... there is likely to be continuing trouble here... remove one of the fish, get a larger system... Read. Bob Fenner> 

Red tiger, albino Oscars fish Hi, <Hello there> I was wondering if albino and red tiger Oscar fish and live with each other? <Yes... given sufficient space... they're the same species> And can a red tiger and albino Oscar fish live with any other fish? Like catfish or something? <Yes...> And if yes can you please give me the names of all the fish the Oscar is compatible with? <Not here... the list is too long. Please read here: http://www.wetwebmedia.com/FWSubWebIndex/fwlivestkindex.htm  and: http://www.wetwebmedia.com/FWSubWebIndex/oscarcompfaqs.htm > Thanks love your site. <Me too. Bob Fenner> Oscar Introduction, or "Hello, my name is Oscar" I hope you can help a friend gave me your email address. Three years ago I got my first fish tank in many years. I've always been a fan of Tiger Oscars so I had three. As they grew I went up to a 90 gallon tank. One died, one sulked and the other got mean. I tossed in a tinfoil barb and all was well everyone got along. Last month my large 12 inch black Tiger died and the 10 inch albino Tiger has been sulking, spitting rocks at me and in an all around funk. Being 10 inches I just couldn't toss in just anything or it would get eaten. He/she was also beating on the pleco's, 2 African knife fish and tinfoil barb. Well two days ago I finally found a new tank buddy who was about 11 inches. A new Albino Tiger. I realized it wouldn't go smoothly and was prepared for a few battles and pushing. What has been going on I was not at all prepared for. They seem to get along great and follow each other around as long as one is moving. There has been a ton of tail vibrations back and forth. I've never seen Curly my first Albino do this before. Phantom the new one is a bit larger and today they started to open mouths wide and go mouth to mouth off and on. Strange since none of my others have ever done this. Just now was the strangest of all. While quietly floating next to each other and vibrating tails what looked like a small amount of blood was released from Curly. This happened twice. Riled Phantom up a bit and they were back to open mouth shoving and a big puffed up tough boy display. Then they go right back to swimming together. Could it be that this new Tiger is of the opposite sex and they are breeding even after only two days? It is all strange to me. I had hoped back when I had three they would breed but no luck. Now all of the sudden there is a new fish and new surprises. Also will the open mouth shoving end? They stopped pushing each other into things about two hours after they were put together. So far only two scales missing and no other marks. Thank you for any help or advice you can give, Jamie <You're a very lucky person. Introducing two large Oscars can result in a broken hood on the floor. I have witnessed the open mouth display many time in cichlids. I believe it is more a way to size each other up than breeding behaviour. More a handshake than a kiss. But the tail wagging and lack of aggression does suggest a you have a compatible pair. And although a little unusual it can happen that quick and smooth. But keep an eye on them. You're looking for marriage, the fish have only spent the weekend together. I have never witnessed nor heard of the blood release before. If the other fish is reacting to it, it may be some sort of hormone release. Usually not visible, but you're looking at very large fish. On that scale it may be visible. If they do breed, you will have to remove all the other fish. They will become very aggressive at that time. If he has a secure cave the pleco may be alright, but will eat any eggs at night. Be thoughtful about breeding Oscars. A large female can lay over a thousand eggs. When they turn into a cloud of fry what are you going to do with them? As in our own species, breeding is great fun! Just be prepared for the resulting offspring. At least with fish you can always set up a tank with a Dempsey or Dovii to solve the problem. Don>

Oscar-resistant algae eater? Is there any kind of algae-eater or scavenger that I could put in the tank with my 12" Albino Oscar, Sleepy Jean.   Her mate died a couple of weeks ago and she seems so sad.  I don't want to put another Oscar in there until I get a bigger tank.  She's in a 55 gallon now. < Your 55 gallon should be fine as long as you have a big enough filter that moves at least 150 gallons an hour. Bigger is better! The more water movement in the tank the cleaner your tank will be. Try and get an outside power filter that is easy to maintain. I like the Marineland brand myself. Look at one of the Emperor filters or something similar. How much water do you change and how often? Algae problems are usually related to high waste in the water. I would get a water quality test kit and test for nitrates. Reduce the levels with water changes.>   I know it's too small and it's probably part of the reason that he died. I need a 100 gallon tank.  I'm working on it.  Until then, is there any type of fish that I can put in there with her to keep her company and possibly help with the algae? < A regular Plecostomus would probably do the job just fine. I would add a PVC pipe from the hardware store that is big enough to let the Pleco in but not the Oscar. The Pleco will come out at night and eat the algae while the Oscar is sleeping. Make sure the Pleco is at least 1/3 of the size of the Oscar. Any smaller and it might be eaten ,or at tried to be eaten by the Oscar.-Chuck> Terri

Oscar tankmates Hi, how are you going < Fine thanks.> I was wondering I could have a couple minutes of your time < No problem, that's what we are here for.>   do you know what fish are fine to have with 2 large Oscars that are 7 inches long in a 5 foot tank thank you for your time < Your Oscars will be bigger in no time and will need all of that 55 gallon tank. Right now I would not recommend you add any other fish. Maybe a 4 inch Pleco if you give him a sheltered spot where the Oscars cant get to him.-Chuck>

FW stingrays sorry about this I will be quick but are stingrays  fine with Oscars or not because I really love them but if they are not I will  give them there own tank so please email me on your thoughts about this thank you very much < This is a tough one. I think the Oscars will leave the stingrays alone and vice versa if they are about the same size. The problem I see is getting enough food to the stingrays without the Oscars eating it all. maybe feeding at night will help. If it looks like the stingrays are getting too thin then separating them from the Oscars may be the only option.-Chuck>

Stingrays with Oscars thank you for your time  do you think that a stingray would be fine with Oscars < I think that as long as they are pretty equal in size they should get along. I would still watch them closely for the first few days to make sure.-Chuck.> thank you

Stingrays with Oscars thank you for your time. I would like to know if you would know it would be possible to out a stingray with Oscars  thank you for your time <Both come from South American rivers so the water requirements should be the same. They should get along as long as they are close to the same size. The Oscar may not let any food sink down to the bottom so you may have to feed the stingray at night to make sure he is getting some food.-Chuck>

Oscar Tankmates Can you please tell me what fish can go in with 2 juvenile Oscars.. they aren't aggressive, unless they are hungry, but I feed them three times a day, so I think they should be fine, but can you tell me all they fish that can go safely with them? >> Many choices in rough and tumble fishes here... other South and Central American Cichlids and catfishes would be my choices... How big a system do you have? Will your filtration handle more load? Bob Fenner

Cichlids <<Greetings, fellow enthusiast...>> As a new aquarium enthusiast, I began about 2 months ago with a 10 gallon setup and within it, 2 Oscars (tiger and albino), 1 small green puffer, 2 Bala sharks, 3 emerald barbs and one 6 inch Pleco. Shortly there after I realized my over population mistake and began saving up for a larger tank. <<Enough said, then.>> As I saved my money, the fish in the tank started disappearing. Strangely, there was no trace of them, no bodies or parts, they had simply vanished. I was perplexed to say the least. One day while sitting down to an evening meal, I watched my Albino Oscar, chase, attack, and swallow my last Bala shark which brought me to a whole new level of enlightenment. <<Ahh... those Oscars...>> That said, I have learned a lot about Oscars in the time between then and now. I have since purchased a 30 gallon tank and recently moved my Oscars into it. <<Erk, did you miss the part that said these can grow largest than your shoe? For certain this 30g tank won't last much longer than the 10g did. Oscars and Plecos both can get quite large, and I mean LARGE.>> (the only other survivor was the Pleco who is also in the larger tank.) My wife thought that a few more fish would be nice so I have recently acquire a small Jaguar Cichlid and another (much larger) Green Puffer. <<Too much for a tank of this size... Oscars being what they are, your biggest challenge will be keeping the water clean.>> With the exception of some excessive fin nipping by the Puffer, they seem to do well, at least until this morning. My Oscars adjusted quickly to the new tank as did the Puffer. The Jaguar did not, for the first three days he hid in the live plants under a thick and comforting blanket of foliage. Not an abnormal re-action I thought considering the change of environment so I left him alone and just kept an eye on him. My smaller Oscar proceeded to chase him constantly during this time but inflicted no damage. Day three rolled about and the Jag had apparently become more comfortable, he no longer hides unless spooked by fast movement and the table have appeared to turn. Upon my inspection of the tank this morning, my smaller Oscar was hiding in the foliage, since he had never done this before I thought it a little strange. As I watched my tank and drank my morning coffee, I realized why. The Jaguar who was half his size was chasing him, and making the occasional brutal hit. So far I have seen no physical damage to the Oscar and perhaps it is just payback for the hazing he issued the Jag upon arrival, but some of the hits were definitely meant with intent to harm or kill. <<Sure... this is most likely competition for space from a fairly aggressive fish.>> I have watched my Oscars for some time now and know their habits and know that they will chase and sometimes nudge each other forcefully. But I have never seen attacks like these even while they were feeding.  Are these fish, when closely sized, good tank mates? <<Perhaps in a larger tank, where each can have it's own personal space/territory, but the Jaguar Cichlid is a known aggressive fish, chances are good that it would continue attempts to establish dominance over its tankmates.>> I already have a larger tank on the way but I am debating if they should be kept together. All of these fish are on the semi-aggressive to aggressive list so I figured they would be decent matches. <<The Jaguar is probably better housed with something that would be more willing to fight back, like a Fire mouth.>> The new tank will be 100 gallons. <<Ahh good, much better size, but still... probably not enough in the long run. Did I mention these fish get really large?>> Also, where can I find good info on Jaguars Cichlids? I search google and turned up virtually nil. <<The Latin for this fish is Parachromis managuensis, you might try your luck at http://www.fishbase.org or even on Google - I just gave it a shot and came up with quite a bit.>> regards, James Williams Jacksonville, Fl <<Cheers, J -- >>

Bala Shark & Oscars <<Greetings, JasonC here...>> First of all I really enjoy your web site, over the past 3 years I have started 3 tanks and your website has given me the most helpful information. <<Glad we can be of service.>> I have a Bala Shark in a 42 gallon tall tank with an angelfish, in my second 73 gallon tank I have 3 Oscars and 2 Parrot fish, The Bala shark is around 5 inches, Could I move the Bala shark into the tanks with the Oscars? <<You could... but would you want to? Oscars really do their part to tax a filtration system, and by adding anything to that tank you're going to add to the bioload.>> The Oscars are around the same length as the Bala shark and the Parrot fish are smaller. <<It would likely work for a while.>> My second question involves my saltwater tank that has the ecosystem, Caulerpa a UV sterilizes, some bioballs and tribase carbon, my Koran angel has started to develop a slight case of lateral line on one side. I have just started to add vitamins to the their food and fish solution from ecosystems. Has my UV sterilizer killed some needed bacteria? <<Hard to say except that it is defiantly not part of the Ecosystem Aquarium as designed by Leng Sy which in my book is a "designed" system - anything else added to, or altered from the original designs will change the results. I would stick with the "system". Only way to know is to take it out of line. HLLE on the other hand is almost entirely nutrition-related. Your best option here is to make sure the angel gets a good mix of foods including something containing marine sponge [like, but not exclusively, Angel Formula] as that is what these eat most often in the wild. Success against HLLE is less likely to come from a bottle than from a well-balanced, natural diet - no terrestrial vegetables.>> Is my carbon removing some necessary trace mineral? <<I doubt that but you should also not leave the carbon in for extended periods of time - so it doesn't become a detritus trap, and the aforementioned reasons.>> Any thoughts would be appreciated Martin Rischall <<You got 'em. Cheers, J -- >>

Tiger Oscars Dear Bob, first thanks for a wonderful and helpful website. I have a 130 gallon short tank with four new two inch tiger Oscars.  <Ah, an adventure> I read one of your FAQ's re tankmates in which you recommend other South and Central American Cichlids and catfish as tank mates. Could you recommend some catfish? I was thinking about putting 2 Vampire Plecos and two royal or leopard Plecos. <Gorgeous choices> If this would work (total of 8 fish), is it necessary for me to buy the Plecos larger than the Oscars?  <A bit larger... these species are slower growers... do train them on sinking pellets/wafers that are algae based... and have some sinking wood for their use in place.> I want to get it right at the start and have everyone grow into their environment. Thanks for your time and help. Linda <Thank you for writing. Make it known how your system progresses. Bob Fenner>

Re: Tiger Oscars Thanks for your quick reply. I just want to confirm that these 8 fish will fit into their final environment. Someone else suggested adding tinfoil barbs for viewing. What do you think? <Well, these are beautiful fast moving fishes that will/would go along with what you have, plan temperamentally and about same water quality. What do you think? Bob Fenner>

Tank mates for Oscars I was recently searching for information regarding my Oscars and hit upon a question on WetWebMedia.Com that someone had asked you that is similar to the one I am searching for answers on. Here goes: I have two Oscars which I have been told are a little over a year old; they are 7-8" long. I have had them for 8-9 months; and after a couple of years of MANY failed attempts to keep fancy goldfish, I am thrilled that my fish (Grouch, as in "Oscar the ...." and Della, as in "Oscar de la Renta") are happy and healthy. I have recently moved them from a 35 gallon tank to a 65 gallon tank. It is a custom build tank made by Tenecor which has an excellent built-in filtration system. The Oscar's only other tank mate at this point is a "Pleco" that is about 5". It has lived with the Oscars since I got them, and they don't bother the catfish at all. So, now that my fish are settled in to their new home, I am wondering if there are any other fish that could peacefully cohabitate with two half grown Oscars and a Pleco. I've been searching around on the internet and found several references of Severums or Jack Dempsey's being recommended as tank mates for Oscars, but I'm not convinced yet. Questions: * Do you think that, given my tank size, its current inhabitants, the size/age of my fish, I should consider adding any other fish to the mix? <No... too crowded as is... unfortunately. A person of substantial ambitions as yourself needs more tank space.> * If so, what are your suggestions? <We could write the proverbial book here. Many other neotropical cichlids, large Characoids, catfishes galore... many more> * Our local pet store had two types of cichlids which my husband and I liked. These were Bumblebee cichlids and Jewel cichlids. Would either of these cohabitate with my Oscars? <As stated, not in the 65> * One last question, if you do think that additional fish are in my future, what is the minimum size fish that you recommend? <Depends on species... a few to several inches> Any input would be appreciated. Thanks much, Susan

Oscar/Texas cichlid I have a 3" albino tiger Oscar and a Texas cichlid in a tank together. I was wondering if these are suitable tank mates. I have heard that the Texas cichlid is very mean and might kill the Oscar, but so far it seems to be the opposite. The Texan just kinda hangs around the bottom and sometimes when the Oscar sees him he will chase him for a bit, but quickly loses interest. They don't seem to mind each other for the most part. They are currently in a 29G but I'm planning to upgrade to a 60G before too long. I've heard some people say they are good together, and some say they don't mix. So I guess I'm a tad confused. Any info would be greatly appreciated. Also I was wondering if you had any info on the Texan because there are barely any on any sites I can find. All I know is that he is the coolest looking freshwater fish I have seen thus far. Thanks for your time. <As far as water parameters go these fish should be fine together. The chasing you are seeing is most likely because of territorial disputes, especially if the Oscar is larger or was in the tank before you added the Texas. They need to be moved into the larger tank ASAP and once they get large you may find yourself needing an even larger tank to prevent the fighting. To find more webpages on the Texas, do a search for the species name Herichthys cyanoguttatus or the more common name Rio Grande cichlid. Ronni>

Keeping Oscar cichlids in the tank Alrighty kids, long time listener.....first time caller. I have a question and then a little "story." <I'm all ears> I've had a few different aquariums thru the years and I want to start a new one. My Oscar committed suicide the other evening (hence the "story") but we'll get back to that in a minute. I like the larger fish, so I wanted to put a green Severum, a parrot fish, and an Oscar.....with a Pleco together? <Parrot is the odd fish out> Is this allowed or will they tear each other apart. <Leave out the parrot, and you may keep the piece for a while.  You'll need 150 or more gallons to do it, though>  Ultimately, I would like to have 3 large fish (could be two of the same fish) and one Pleco living together in perfect harmony (Any thoughts?) <Achievable!  It's what we all stride for.  A biotopic display is your best chance at peace.>  I like fish with character. The four I chose are the ones I like a lot. Once I figure out the fish that can be together, I will get the proper sized tank. Any inkling of info on this matter would be greatly appreciated. <Get them young, hope for the best.  Oscars aren't mean spirited, per se, they're just consistently hungry.  A pair of Oscars and a large Pleco is going to require a huge commitment on its own...And a killer bioload depending on your filtration>  Now onto the story.......My Oscar was about 10" long, so the other day I wake up and come down stairs and what do I see laying on the floor quite a few feet away from my tank!!? That's right, my Oscar. Somehow he knocked the entire hood and light into the aquarium (yea I know, hoods with the light on them are heavy) and then tried to dodge the falling debris and ended up on the floor. <Ouch> Alas, I am saddened.....but what can you do, but to move on and forge ahead.<Too true> Ergo, starting a new bigger and better tank with latches on the hood, lots of latches, latches with chains hooked to them and then wrapped around.......<Ha!  Better not let the Oscars see the combination on your Masterlocked tank!  These things happen-To our dismay.  I think you'd be more successful with a species tank.  If you like fish with personality, check out the Tilapia butikoferi.  Must be housed alone, but it's a great "Bad boy."> I look forward to hearing from you kids. <And we look forward to hearing back from you!  Until next time, Ryan>

Plec for an Oscar tank Dear wealth of knowledge, I have a 75g freshwater tank which is currently empty.  I am thinking about purchasing either 2 red Oscars or 1 red Oscar and 1 tiger Oscar.  My question for you guys is what my options for a "clean-up" Pleco are, keeping in mind tank size. <I assume by "clean-up" you want something to eat algae, right?  This in mind, I'd suggest the royal Plecostomus, Panaque nigrolineatus http://www.planetcatfish.com/catelog/loricari/panaque/151_f.htm .  This is a pretty good grazing Plec, and should do a number on algae; will likely need to be supplemented with greens (like blanched zucchini, for one).  It'll also require driftwood, without a doubt.  And might be a bad choice for a Plexiglas tank, as they have teeth that'll wreak havoc on plexi, leaving scratches.> I also wanted to know a little about freshwater (red tail) barracudas.  I have found it a little difficult to find info on them.  I am wondering about tank size, compatibility, and how prone it is to disease.  Thanks a lot!  Zack <Do you happen to have a Latin name for this guy?  Right now, I'm inclined to think you mean "Acestrorhynchus falcatus".  Try looking this up on fishbase.org, and do a google search on this name to see what info you can get.  Wishing you well,  -Sabrina>  

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