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FAQs on Arowanas Compatibility

Related Articles: Arowanas, Bony Tongue Fishes, Arowanas, Arapaima, African Butterflyfish, Featherback Knifes, Mormyrids, Elephantfishes

Related FAQs:  Arowanas 1, Arowanas 2, & FAQs on: Arowanas Identification, Arowanas Behavior, Arowanas Selection, Arowanas Systems, Arowanas Feeding, Arowanas Disease, Arowanas Reproduction, & Bony Tongue Fishes, Aba Aba Knifefish, African Butterflyfish, Arapaimas, Featherfin Knives, Mormyrids, New World Knifefishes,

My Arowana Tank (.com)


Arowana; comp., selection questions     3/24/16
Hi crew
I was hoping you could clear something up for me on Arowana. I am an Arowana collector of sorts. Love these fish.
<Fishes; more than one species... All of the same, or simply one is denoted as "fish">
Currently I have 2 jardini, a liechardti and 4 silvers in the same tank, a new Amazonia biotope and it's around 4500 gallons with a baby Arapaima before he goes to my friends pool.
<Arapaima gigas eats Osteoglossum spp. in the wild. And mixing Arowana/Aruanas, species (plural and singular) can be problematical. They fight>
I as you can see by my list don't have a black Arowana. I really want one too. Do all black Arowana get that blue coloring and keep it or do they all look like silvers when fully grown?
<The latter as far as I've seen... a little duskier, mostly underneath than silvers with age>
If you can tell me their color changes or how to keep more of their black color they have as juveniles it would be very helpful
<Can't be done as far as I'm aware. Unlike Scleropages formosus, South American Arowanas haven't been cultured, manipulated to "fix" color morphs (yet). Bob Fenner>
re: Arowana        3/25/16

Yes the Arapaima is being moved soon.
<Ah good>
He is about 2' and the Arowana are all around 4' except the Australians.
So if I buy a black Arowana that's blue, it too would loose it's color and look like a dusty silver?

Arowana; comp.; fdg.       2/23/16
Hi crew!
I have a silver Arowana and am aware of its size
<Good, because these things are massive, and more importantly, don't adapt nearly as well to captivity as the Asian Arowanas.>
and yes I have a big enough tank for it, a 500 gallon just for it when I can put my red tail catfish back outside for the season.
<Sounds like a good plan.>
It's about 13" and I have been having trouble getting it to feed.
<What are you offering?>
It will eat anything, but not off the surface of the water.
<Curious. Try crickets or mealworms. They usually attract their attention.
Is there anything else at the surface? Something that might be threatening it? Have you tried moderating the lighting a bit? Very bright light probably isn't helpful. Floating plants give them something to explore, and if you starve the Arowana for a week or so, then add some floating food or even crickets/mealworms, he'll have to forage up there.>
It will wait for the food items to go down to the gravel bed and then will go eat it.
<Well, so long as it's eating...>
There are Oscars, a jaguar cichlid, a gar, and 2 clown knives in this tank as well and they all go down to the bottom to feed so then I offer the Arowana food at the top and she sees it, ignores it and feeds off the bottom like everyone else.
<Sounds like learned behaviour.>
I have tried strictly floating pellets and she still wants her food at the bottom. I don't want her developing drop eye from feeding off the bottom of the tank as she is a lovely albino and worth a lot to me sentimentally.
<Understood. Here's the thing. Drop/Droop Eye in Arowanas is extremely common and nobody really knows why. One argument is that Arowanas focus where the activity is, and if it's below them, their eyes "lock" in the droopy position. So if tankmates are at the bottom, that's where there attention will be. Keeping them on their own, or only with surface dwellers, and exclusively feeding floating foods, should help if this is the case, and to some degree it does. Drop/Droop Eye really is
characteristic of Arowanas kept in smallish tanks with midwater and bottom swimming tankmates. The second argument is that Drop/Droop Eye is dietary, with excess fat or some sort of vitamin deficiency to blame. So focusing on a leaner, more varied diet will help here. Finally, there's the argument it's caused by trauma, whether physically bumping into the glass or
something more subtle like water pressure. If this is the case, avoiding fright responses (no tankmates) and providing the biggest possible enclosure will be part of the prevention. These are all ideas, and you'll need to research them all, but I think you can get some tips from how zoos keep them. Very big, deep tanks with subdued lighting and few tankmates.
Diet is very carefully managed, and often a lot less than home hobbyists provide.>
I am also looking for a monster catfish for my indoor pond and have narrowed it down to red tail catfish and Tiger shovel nose. Which one is generally smaller (relative term for both) and easier to manage?
<Tigers are longer than RTCs, but tend to be leaner, so there's really not a lot in it. Neither makes a good aquarium fish, though of the two, the Tiger Shovelnose has perhaps the (marginally) better track record. But even with 500 gallons you're basically keeping a horse in a suburban back garden, so there's a great many catfish I'd look at before either of these.
Adonis Plecs or example, or a school of Sorubim lima. All sorts.>
I have weighed to pros and cons of both and I am wondering which of the two if you had proper facilities for both which one you would pick. Thanks
<I'd pick neither, but then I'm a conservative fishkeeper! Cheers, Neale.>

How big? Symphysodon/Arowana comp....  -- 4/12/10
Hi crew,
How big do you guys think my discus should be before I try to put them in with my 14" silver Arowana?
<Oh, about 60 cm/2 feet across. Seriously. Keeping Discus with Arowana is insane. Who told you that would be a good idea? That person needs his bumps felt! Symphysodon and Osteoglossum spp. come very very different
environments and have very different needs. Discus come from slow-moving, very warm water; Arowana come from big river channels with strong water currents and moderate temperature. Silver Arowana are fairly peaceful, but they vary enormously, and some specimens can be extremely aggressive.
Rehoming a subadult Arowana that's been battering your Discus will be easier said than done. On top of that you need to feed a lot of food to an Arowana to keep it healthy. But you also need to get food down to the Discus without the Arowana eating it all. Given Angelfish steal food from Discus, heaven knows how hard it'll be for the Discus to compete with an Arowana! Regardless, the resulting high nitrate levels from all this feeding will cause real problems for Symphysodon. I can't see any sensible way of keeping the two species together in the long term.>
Currently I have 5 clown loaches in the tank that measure from 1 3/4" to 2 1/2". The Aro looks at them occasionally but has never shown any aggression that I've noticed.
<So far. Silver Arowana are not viable home aquarium pets. Osteoglossum bicirrhosum gets to 120 cm (about 4 feet) long in the wild, though around 100 cm (3.3 feet) is more typical in aquaria. The minimum aquarium for one
of these monsters is 2500 litres (660 US gallons). Given how big they are, that tank will need to be at least three times the length of the adult fish and at least as wide front to back as the fish is long; that's about 3 metres (10 feet) long and more than a metre (3.3 ft) broad. Osteoglossum can be highly aggressive and will eat anything they can swallow. Adult Clown Loaches might be okay, though the usual tankmates are large Loricariidae, such as Acanthicus and Panaque spp. Most Osteoglossum end up stunted and damaged by being kept in too-small aquaria. Shame really, because they're lovely fish.>
My discus are 3 1/2" tall.
<Arowana food.>
Please tell me what you think.
<I hope you have a REALLY big aquarium.>
Thank you.
<Cheers, Neale.>

Arowana and Silver dollars in a big planted tank, sys.  2/29/08 Hi, I have a question that has many different angles to be looked at. I have been reading your website for the past 2 or 3 years and have scoured about 50% of the freshwater info as I have found it invaluable. First off, I have a pretty big L shaped aquarium, 8 ft long, 45 degree angle of 4 feet, then another 45 degree angle of 8 feet with the tank being 2 feet deep and 2.5 feet tall acrylic tank (about 900 gallons +/- 50 from evaporation etc.). Ammonia and nitrites are of course zero, nitrates are between 20 and 40ppm (attributed to nitrate factory type trickle Bioball sump), pH at a steady 6.8 attributed to the large pieces of driftwood I have in their and their tannin releasing ways, hardness is at 80ppm. Temperature ranges from 74 to 76F in the mid to upper levels, 72-75F in the lower levels, due to lighting I guess. Filtration turns the tank over about 5-6 times an hour, though with cloggy filters, maybe only 3 times an hour. <Does sound like you need to upgrade the filtration a bit; in all honesty jumbo fish need all the turnover you can get. I'd be looking at 6x turnover minimum, and likely 8-10. If water quality is basically sound, you can perhaps get away with just adding a powerhead or two into the tank to keep the circulation of the water even.> It currently houses a foot long silver Arowana and a school of 11 silver dollars (the smaller 5-6" ones, not the red hooks). I also have 4 fairly young (only 1 foot tall, about 20 leaves) Amazon swords planted in 2 inches of gravel, and a whole bunch of Anacharis that's growing like a weed (for the silver dollars munching pleasures) though it is growing much faster than the fish are eating them. <Sounds great!> I also have some powerful full spectrum lighting across the two 8 foot lengths of the tank, nothing in the middle of the L. My more concerning question, or more likely, situation, is that my Arowana (I've had it since it was around 5") recently started taking dives at my silver dollars as they swim on their merry way beneath him. Is this a show of territoriality or is he trying to eat the silver dollars or both? <Either. Both. Arowanas are territorial and object to anything in "their" zone of operations. This varies with species, and Silver Arowanas are very much at the mild end compared with, say, Scleropages jardinei. But on the other hand that doesn't make them friendly community fish! If the Arowana is sufficiently big, it may be trying to eat them, or at least "sample" them to see if they're edible. A 6" Silver Dollar is borderline when it comes to safety with an adult Arowana. Some people have mixed them fine, I know; but look at how big the mouth of an Arowana can get! I wouldn't be 100% comfortable with this combo.> The silver dollars are way faster than him though so I have not yet scene what happens when he catches them. He is usually just silently sitting beneath a carpet of Anacharis during the day and only moves when fed (Hikari Arowana pellets plus weekly beef heart, plus whatever flakes, crumbles, bloodworms I feed the silver dollars) or when the lights are off. Also, I read that Arowanas generally leisurely patrol the aquarium all day and I figured now that I finally built my uber aquarium (oh that's right, self made... 20% of the retailers price... plus several cases of beer and pizza for friends who assisted in heavy lifting. <Ha!> Is it possible that my lights are too bright and the Arowana doesn't feel safe or its hurting his eyes, though he did just swim around normally for about a month until he started to "hide"? They are power compact fluorescents, 525 watts per light fixture, 4 total fixtures. This is a major concern to me as I have been keeping fish for the better part of a decade wanting an Arowana but refusing to get one until I could house it properly and now he just sits there. At night I have moonlighting and he does then move around quite a bit, this is why I suspect the lighting, but I never thought they were nocturnal... more diurnal from what I read. <Difficult to say on this one. Arowanas are noted for being photophobic, though most fish prefer shade to bright light. Do all the lights come on at the same time? Sometimes fish get alarmed by that, and having the lights come on across an hour makes a big difference. It does sound like he doesn't like the light. Is adding an understory of plastic plants (there are some great 3' plastic plants available now) an option? Something that could drape across the surface and cast some more shade? I suppose the experiment would be to unplug one light fixture for a day or two, and see if the Arowana prefers that end of the tank.> My next question has to do with the silver dollars and them seeming to enjoy eating the Amazon swords more so than the Anacharis. Is there some other large show plant that does well under high lighting that the silver dollars wont want to eat? <I'd perhaps look at Crinum spp., e.g., C. calamistratum, as these do seem to be left alone by herbivores. They're big and generally hardy. Java fern will do great under bright light, though it does tend to become an algae magnet. Anubias even more so.> Also, my swords aren't exactly growing as well as they had in past tanks with 4-5 inches of gravel. Does the gravel depth make that much of a difference? <Yes; also the quality/composition of the substrate.> I have something like a thousand Malaysian trumpet snails aerating the gravel and what not but am concerned that if I add more, the snails just wont be able to irrigate and aerate all that gravel, and the last thing I want is some anaerobic environment unreachable by plant roots or snail burrowing releasing poisonous hydrogen sulfide and the likes into my tank, plus stinking up my fish room. <Just doesn't happen. The "anaerobic decay" thing is largely a myth. Happens naturally in ponds and in marine tanks (inside living rock) and no-one fusses. So by all means ramp up the depth of substrate to what worked before. Do also check first that the substrate is adequate though -- Amazon swords want a nice rich soil or laterite enriched substrate, and plain washed gravel just won't work for them.> Should I consider ditching the silver dollars for a school of tinfoil barbs? They don't eat plants at all do they? <Tinfoil Barbs can, will eat plants.> And lastly, as you may have guessed it, I want to add more fish to this tank as it seems fairly empty... I'm thinking black ghost knife? <In theory fine, but you'll be hard pressed finding an adult large enough for this community. Mostly you only see baby Apteronotus for sale.> I first filled up the tank about 8 months ago, filling it with something like 100 Malaysian trumpet snails and about 20 mystery snails for my tank cycling. I over fed the snails for 3 months in order to obtain the current population explosion of snails I now have, <Consider adding a group of Clown Loaches or thorny catfishes (Doradidae). These will eat the snails, if sufficiently hungry.> at the end of month one I added the sword plants, then I added the silver dollars at the end of month 3, all at about the size of, well, silver dollars. They mostly hid in the center decor castles of my tank for the first two weeks but then began to sprint (if you will) from one end of the tank to the center and back (they seemed to never travel into the leftward portion). After having them in there for 2 months, they had grown to about 3" in diameter each and I added my Arowana at 5". After only another 3 months the Arowana (from what I could tell) doubled in size, which I attributed to it having so much space to swim. <Or simply good maintenance. Arowanas grow quickly if kept well.> Now I added the Anacharis about 2 weeks after the Arowana was added and it was generally ignored by all but a couple of snails. Then a month ago (beginning of month 7) is when the Arowana began to just sit under the Anacharis. So yeah, back to the black ghost knife... I want to buy two of these guys (I figure the tanks big enough) and I put two PVC condos with 15 pipes of 2" diameter and 1' length in there, one in each 8' portion. Should I be concerned about the Arowana eating them as I often find the knife fish around 4-5 inches in length max, and it will be some time before they grow to their 2' potential where the Arowana wont (hopefully) eat them. Are the black ghosts fast enough to evade the Arowana if pursued? <No; sooner or later, if they're small enough to swallow, they'll be eaten. The Arowana only has to get lucky once!> And for the record, despite clown knives growing huge and not being swallowable by my Arowana, they will probably eat my silver dollars and knock over my plants, and just grow too big for my taste, so that options out. <I agree.> Well, that's all for now. I literally read all over the web for months and abstained from just writing you guys since I know how annoying it can be to be asked simple questions that have their answers everywhere... but I just cannot find anything like this Arowana diving at silver dollars thing while not swimming anywhere else. I am a student of the sciences, my job being that of a biochemist, therefore I was cocky, stubborn, and reluctant to ask for help (a character flaw repeatedly pointed out by many over the years)... but there are just some things you cannot learn in books. I'll likely have another question or comment in a couple of months after the knife fish are added... if they are compatible. Thanks in advance for any advice you can provide. With Best Regards, Matt <Hope this helps, Neale.>

Re: Arowana and Silver dollars in a big planted tank (RMF, please comment)  2/29/08 Well It looks like I'm going to be upgrading my sump pumps using some pond pumps to get that water flowing up to the 10 times over level. I currently have four overflow filters going into four 55 gallon tanks... I guess I will just have 4 extra pumps to sell on aquabid.com as I replace them with the pond pumps. The pumps I have looked at are reporting 1800 gallons an hour (Danner Supreme Mag Drive Aquatic pumps, I currently own the 1200 gph pumps)... am I going to need larger sumps or will this push through the 55 gallon tanks just fine? <No idea; RMF, any thoughts?><<I would definitely be reading, making careful choices here... There is much to be saved in the way of electrical cost, pump noise, waste heat, service life, by making good decisions re pumps... The Sequence series/Baldor motored lines are some faves for the size, application here. Other fractional horsepower pumps are ably reviewed here on WWM: http://wetwebmedia.com/pumpselmar.htm and the linked files above. RMF>> This company also sells a 5000, specifically designed for large ponds and waterfall displays which reports 5000 an hour. Is that overkill or should I add one or two of those in too? I guess two 1800 and two 5000 gives me 13600 gallons an hour claiming about 15 times an hour for the whole tank... realistically maybe 11-12 times an hour turnover? <Probably overkill. 8-10 times turnover should be adequate.> As for the silver dollars not being fully compatible, I will look into giving them a new home. I have just been keeping silver dollars for 7 years now and figured I was pretty good at it. My last batch of 7 didn't die, with the oldest being 5 years old starting in a 55 gallon and moving up to a 120 gallon for the remainder. I just gave them to the LFS before I moved halfway across the country for the job that would allow me to have such a lavish aquarium. What other fish come to mind, that would be an attractive school of 15-20, that could be raised in one 8 foot section (separated by a divider) until large enough to not be eaten by the Arowana? I'm thinking Bala sharks? <A good choice. But also Semaprochilodus taeniurus look amazing in large groups, and are nice Amazonian fish.> I read they get to 12-15" and from my limited experience, are very fast. <Oh yes.> Do they eat plants because I cannot find info saying that they do, but then again, I was wrong about the tinfoil barbs. <Balantiocheilos melanopterus generally ignores plants. It eats green algae and invertebrates, and may nibble on tender shoots, but that's about it.> Maybe 6 months separated, grown to 7-8 inches then set to survive with the Arowana? <You may also be able to get adults via Fish Forums, fish clubs, etc. Lots of people buy them, and then have to rehome them when they get too big.> Are their any other fish you could recommend as I have limited experience with large schooling fish. <There are a lot of nice big barbs. Severums would also look quite nice, and occupy the midwater. They're territorial when spawning, but your tank is big enough that shouldn't be a problem. What about catfish? Sorubim lima is a nice big (45 cm/18") schooling catfish. It's very peaceful, pretty, and quite easy to obtain. It famously likes to swim vertically leaning against plants and rocks, so is definitely fun.> As for the lighting, the timer IS set to go on all at once come 10am and turn off at 8pm. Some sunlight does come through the one window and glass door to wake the fish up, but I guess that is nothing compared to a full 2000+ watts blazing into their eyes all at once. I can turn on the actinics at 10 am, then 2 of the other full spectrums on at 11, and the rest at 12... and then shut them off in the same manner (off to Home depot again for more electric timers). I assume this will still be ample light for the Anacharis and Amazon swords. <Should be. Try it, and see what happens!> And I do have two 3 foot plastic plants draping across the top of my tank which cover an area of maybe 4-5 square feet each. They are located in between the Amazon swords as to not rob them of light. I don't really want to put much more over the plants, but there are still many other places in the tank to add another 4 to 5 of those 3 footers without disrupting light to the live plants. I will give them a try since they are cheap and fairly realistic looking. As for the other plants, I do have an Anubias growing on a piece of driftwood, though the plant is 3 years old, started as 3 leaves, has maybe 30 now, and has only moved about 1 foot across the driftwood (3 foot long driftwood). It used to be house with a Pleco so perhaps his constant sucking of the driftwood would constantly cull the Anubias... or maybe the thick film of algae growing on its leaves is inhibiting it? <I've tried Anubias with my Panaque, and it gets turned into a Swiss Cheese Plant, so I agree with you here!> Ill try out the C. calamistratum when I find it. If nothing else the LFS can order it for me. <Mail order plant distributors abound, and this is a fairly common species, at least here in the UK.> I do have a Sailfin Pleco in there too. He's only about 8 inches long though so he is having a problems stopping all the algae as of yet, though I have faith in him (or her, I cant tell yet). <Once they mature they aren't really algae eaters, so don't hold too much store by this. Plecs generally are omnivores, and algae is only a part of their diet.> As for my substrate, it is just painted black artificial gravel. I add trace minerals for the plants, but I guess that's just not going to cut it. <Indeed.> It will take some time to clean all 200+ lbs of gravel out, but I would say in half a years time I should have 4 inches of laterite enriched substrate in there. <Can't begin to tell you how much I sympathise! Anyone who has grown aquarium plants (or tried, at least) will have been through the mill of changing substrates.> I guess I wont be getting the black ghost knife anytime soon, if ever, aw well. <Again, look out for "second hand" specimens.> Maybe I'll get some water in my 120 and raise him in there until he's big enough for the show tank. <Quite.> And perhaps I misspoke about the snails as a pest, as I want them in their. I have never been able to keep a tank as clean as I do when I have snails in their. <I wonder if Apple Snails would help on the algae front?> I once had a tank with 4 yoyo Loaches in there that cleaned out the snail population, there was a gradual decline in water quality, and an increase in detritus and algae that I fought for a year... I removed the loaches to the LFS and my tank recovered to crystal clarity in 3 months time. <Not impossible.> Therefore, largely based on this single experience ( I know, that's poor scientific form) I like to always have snails. And despite the appearance of (now about 100 mystery snails) snails crawling all over my tank with about 1 snail on every 4 square feet of glass (or I guess acrylic), I find it more peaceful and artful than an eyesore. <Indeed.> It looks to me as though your experience in the trade has done it again. Thank you very much for your assistance. Matt <Good luck, Neale.>

Re: Very Sick Arowana update!  11/16/07 Thanks for the response! First off let me say I am taking your advice and all the Jardinei's are going! The largest Jardinei is getting very aggressive and herding the 3 smaller ones to the bottom of the tank. <Indeed. This is what they do.> The largest jardinei is being sold to the owner of a LFS in 3 days. <Good. They're lovely animals -- but one to a tank!> The others I will get rid of ASAP with care of course. <Good. You will find that the largest male left behind will become aggressive, and so on as you remove them.> Then the silvers (hopefully 3 not 2) are going to be moved to the 430 gallon until they grow a little bigger. <OK.> Now as for the sick silver. I isolated him for 5 days in the plant refuge and treated him per instructions with 2 packets of 200mg Erythromycin, aeration, and a daily 25% water change before each daily redose. The mouth wound or infection has healed considerably and has lost its fuzziness and just left the slight erosion on the end of the lip. <This will heal in due course, but some scarring may remain. Often the "new" skin has a different colour to what was there before. This is particularly commonly seen in fins, but can happen on the body as well.> He appeared to be swimming fine and a lot more active but will not take food. <Not a problem in the short term. More important he heals.> So I placed him back in the main tank hoping it would encourage him to eat. <Which he won't if he's being bullied there. I'd keep a sick Arowana on its own. Really, they're best kept alone anyway, and if you going to mix them, they all need to be healthy.> He has not eaten for about 7 or 8 days now. How long can they go without eating? <Several weeks. Do try alternate foods. South American Arowanas have a great fondness for insects, so try offering a variety of different insects. Beetles are apparently their favourite food. River shrimps, if you can get them, are also excellent, and few predatory fish ignore earthworms. Don't worry too much though. When the fish is healthy, it will eat.> Now back in the main tank I watched him closely for several hours. During the day he was horizontal and swimming with a slight waddle. After the lights turned off at night I found him vertical again. He would curve or coil his tail up and try to touch his body. At one point he was swimming in a out of control spiral. After a while he would be back up top swimming normal. Then back on the bottom head up again. I have looked him over very closely. His fins look perfect! The only thing I can see is a small red tinted spot approx 1/8 -3/16" in diameter which u can barely see. When he was still I looked closely at it with a flash light. It appears to have a pin head little spot in the middle of it. This is the only thing I can see on his body. I have attached a few large pictures now if that helps. <Please next time send smaller photos -- it takes forever to download 14 MB of photos via an e-mail client. We do explicitly ask for photos no larger than a few hundred KB each.> The first picture is when I placed him in refuge for treatment. The other night time photos where just taken (last 2 show red spot on lower jaw / gill area. What do you think?? Should I treat for fungal, parasites, or different bacteria? Again thanks for your time. Sincerely, Robert <He needs to be moved back to his own tank and kept there, end of story. Get the fish settled down and healed. I don't think there's any seriously wrong with your fish. It's noticeably underweight, yes, but that's easy enough to fix with a mixture of live invertebrates and good quality pellets. The antibiotics or antibacterials will take care of the secondary infections. My guess would be this fish is at the bottom of the pecking order, and putting it into the big tank is simply futile. It's a fish that needs its own tank where it can swim about and feed naturally. Ultimately you can't medicate this problem away -- it's a question of husbandry. Arowanas are not schooling fish in the wild and they are not sociable fish in aquaria. They are territorial loners, and the males especially are pretty nasty towards one another. What you're trying to do is fight against nature, and that's a battle I don't think you can win. If you happen to get a few specimens that coexist, that's great, but there will likely be specimens that will not coexist, and they will HAVE to be re-homed. Cheers, Neale.>

Arowana compatibility, sys.    12/28/06 Hello there, and happy holidays! <And to you and yours> My family currently has a lovely Arowana at about 19" in length. He's been living in a 46g tank, <!> but we're getting a 100-125g tank soon. <And larger soon afterward I hope/trust> It's about 60" in length, would that be a suitable length for him, since he's the only Arowana? <Not really... may/might I ask, would you like to live in a world that is four times your length?> I've read in other sources that they may develop eyes that turn downwards from being overfed. Is that true? <Mmm, not really from being overfed, but more as a consequence of captivity period... living in small containers, looking downward... running into objects...> He does have a slightly bulging eye (his other eye was damaged & it's blind), <...> but I don't believe we overfeed him. He's on a diet of Hikari Food Sticks, a random assortment of flake foods, bloodworms, and random bugs/earthworms. <ditto...> As far as other fish for the new tank goes, we're a bit uncertain as to what he'd take kindly to. Our local retailer says that teacup rays are suitable (we'd buy only one), <... well... found in S. America... this is... a start... and do tolerate/appreciate similar water quality> and since they're both from the same region, their preferences for water types and everything are similar. Is this true? <Truth? Scarce can I name but fearful thunder echoes in mine ears...> What kind of gravel/sand substrate should we use, is there a recommended type? <Most anything that fosters biological filtration... Covered on WWM> Also, for the simple fact that they have barbs... how likely is it that they might injure the Arowana or us? <Barbs? Osteoglossid fishes? Mmm... not to worry> And also, how much should we expect to pay for a teacup stingray in NJ, USA? <Perhaps a few tens of dolares per unit> Another fish we considered was the Silver Dollar (a group of 6, at about 4-5"). Though I think they seem a bit small because of the Arowana's presence, <Agreed> the store owner assured us that because they're so round and fast, they're safe. <Getting past time to look for/at other LFS's> However, if they are so fast, would they stress the Arowana out? <Yes> And wouldn't he still bite at them, perhaps not to kill, but still causing a sufficient amount of damage? <Too likely in a small volume> As for the tank itself, I tend to stock mine heavily with plants. Would the ray uproot it all, and the silver dollars devour them that quickly? <Very much so...> What sort of balance should we aim for? <My friend! That is beyond me... perhaps yourself!> Thank you, Christina <Thank you, Bob Fenner>

Jack Dempsey vs. Arowana   9/19/06 Hello, Best site I've come across!!! < Thanks for your kind words.> I'm a new aquarist, so this may seem like a silly question. I have a 30g freshwater tank with a 6 in. Jack D. that is quite interesting. I feed him all sorts of food & he is aggressive when feeding. I really want an Arowana, but have read how aggressive they are. I plan to start a 150g in about 6 months. Do you think this might work? Thanks for any info-Joe    < Am afraid the Jack Dempsey may not tolerate the Arowana and may harm him. This will be up to the individual temperament of the Jack Dempsey.-Chuck>

Arowana and Ray Biotope Tank Hi, I'm setting up a 225 gallon Arowana tank with Rays. <Even though 225 gallons in rather large, it is still a rather small tank in comparison to the fish you selected. I do not think you could safely stock more than two of each.> I would like to use a few live plants to make them a little more comfortable. <I think the Rays would wreck any live plants.> If I am only using a few plants how much fluorite should be used <I would stick to a sand bottom for the comfort of the Rays.> and what kind of plants. <Perhaps you could grow some Java Fern attached to something. There would be little danger in it becoming up rooted.> Thanks, Dave <Good luck! -Steven Pro>
Re: Arowana and Ray Biotope Tank
Thanks for the info and the 225 is only for 2 years until we build our dome home where there new tank will be the circumference of 30' by 3' wide 4' tall with a main tank connected at one end 10' x 4' x 4' <Wow! Truly impressive concept. Do send us pictures when done. -Steven Pro>

Arowana with a Moray Eel I have recently purchased an Arowana and a Fresh Water Moray Eel( looks just like the one in the picture). <Not a good choice to mix these two very different fish from very different environments.> After reading through the articles on the Eel, I understand that it prefers a brackish water more. Right now I have a 55 gallon fresh water tank. <The 55 is way too small for the Arowana, my friend. Your LFS did you a disservice by selling you a fish that needs a standard 180 as an absolute minimum.> PH is between 7.6- 8.0, Nitrate is fine and the there is no Ammonia, at a temp. of about 80 degrees. What should I do, will adding some salt water to accommodate the Eel effect the Arowana? <You are not going to be able to strike a happy balance for these two. My best recommendation is to return the Arowana and turn your 55 into a brackish tank.> For this tank what would you recommend everything should be at. Thanks for your time. <Further info can be found here http://www.wetwebmedia.com/FWSubWebIndex/osteoglossiforms.htm
 here http://www.wetwebmedia.com/fwmorayeels.htm and here http://www.wetwebmedia.com/bracsetup.htm
 -Steven Pro>

Discus with Arowana 10/18/05 Hey, I was just wondering if you could mix Discus's and an Arowana together in a 100gal tank.  thanks. >> You can, if the Arowana is still young. Once the Arowana reaches around 16 inches in length it will have to be moved. For that matter, a 100 gallon tank is too small for an Arowana at that size. Good Luck, Oliver<<

Compatibility questions & miscellany... Mainly Aruanas... sys.  - 06/30/06 Hey there, thank you for the reply last time, it was really helpful. <Welcome> Bob had previously helped me identify my Knifefish as Sternarchella schotti, which seemed dead on correct. However, he has continued to grow past the 8" mark; he's about 11" now... is there perhaps another species that he could possibly be, or is he just an abnormally large example? <Could be... either possibility> We also used to feed him various foods, ranging from bloodworms to shrimp and everything in between. However, I've been busy this year (blahh, junior year of high school is evillll) <Correction my young friend. Only certain acts are evil... not individuals, school time frames... Though...> , and my father's rather lax about fancy feeding... <Careful here...> so we hadn't given him live food in ages. When we did start putting in live food again, he showed no interest at all... is there any way we can get him to start again? <Mix some in with the prepared foods... over time...> My father also purchased an Arowana (silver) while I was away at school. Since they both like softer, slightly lower pHs, so I left them together; they haven't fought once. The Arowana is about 13" now. What are the chances of him bullying the Knifefish, or vice versa? <Very small... Perhaps if/when the Arowana is large enough to ingest the knife...> We also have a gold Gourami and Pleco in the tank, both about 5" long or so. <Oh, the Gourami will be inhaled first> Recently, the Gourami's been somewhat subdued and injured... Nothing serious, but there's missing scales and slight dents along his back. <Oh, it's time is coming> Somehow, an Arowana attack doesn't seem like it would leave those marks, and neither does a Pleco or Knifefish. The water conditions are the same as always (pH about 6.5, soft water, well planted and shady), and are holding steady. We have a few cichlids in another tank that are about 5" now, and were wondering if they could get along with the Arowana/Knifefish. <... depends on species, the size of the tank...> I think (though I'm not sure) that the salinity and pH and everything are quite different though; would they be able to coexist healthily/peacefully? <See above> Our Arowana has a few unfortunate things, though. He's been blinded in one eye (which has made him more docile but slightly jumpier) after smacking into the floor before we learned to clamp down the top. <... happens... all the time> He doesn't swim noticeably different, but most of the time when he lunges for food, he'll just barely catch it or miss. He hasn't lost condition though... he's still a fat and constantly hungry pig. But...How should we help him compensate for this, if at all? <Mmm, bigger/est tank, careful feeding of cut foods offered on/with a dedicated "feeding stick"... good maintenance otherwise> The other thing is that the person who sold us the fish told my dad that he would grow to fit his tank. <... uh... no> Disillusioned, my dad thought he'd be fine to stick in a 46gallon tank for the rest of his life, <Not a very good or long one...> especially since he was only about 6" long when he bought him. However... I'd like to know my options for him, just in case. We don't really have the resources for a larger tank, maybe 60g at the most. <... needs hundreds of gallons minimum...> I'd be willing to try and sell him back, or send him to another place, but I'm not sure if his eye will affect his ability to do well there, and I've grown somewhat attached. ^^" If we need to send him elsewhere, are there facilities that we can do so? <Maybe> Are there Arowana species that would be able to fit in a 46 gallon tank comfortably? <No. Please read here: http://www.wetwebmedia.com/FWSubWebIndex/osteoglossiforms.htm and the linked files above. Bob Fenner> Thank youuuu, Christina
Re: Compatibility questions & miscellany  - 06/30/06
Eep! I'm sorry, for the 2nd to last question... I live in NJ, USA, if that helps at all. I'm not aware of any public aquariums or NON-commercial pet stores around here, though I'd be more then willing to drive a bit more for him, heh. <Mmm, give the large/r stores and Service Companies in the "Aquarium" section of your local Yellow Pages a ring re... perhaps they'll know someone with facilities, interest. Bob Fenner>

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