FAQs on the Piranhas, Pacus, Silver Dollars and their Relatives

FAQs on the Piranhas, Pacus, Silver Dollars and their Relatives

A Mylossoma duriventre in captivity.

Live Plants with Silver Dollars? 3/21/08
Hello. I have a 55-gallon community tank with two silver dollars. I also have a Pangasius cat, a rainbow shark, two giant Danios, a striped African glass cat, two dwarf gouramis and a small Pleco, I have plastic plants in the tank and the fish seem to avoid them and treat them almost like an obstacle when swimming. They occasionally use them for shelter.
<Hmm... you *are* overstocked, in particular because of the Pangasius. On the flip side, African Glass Cats are schooling fish, and they'd be happier if you kept 6+ specimens.>
I'd like to switch to live plants that can provide some habitat but I know that silver dollars are vegetarians. Are there any live plants with sufficient foliage, etc. that silver dollars will not consume?
<Not many! Very sturdy species including Java ferns, Anubias, "giant" Vallisneria, Crinum thaianum and some of the hardier Crypts such as Cryptocoryne ciliata are species that sprint to mind. Floating plants
usually do well with vegetarians, in the sense they grow rapidly enough to offset being eaten, particularly under bright light. So Amazon Frogbit, Indian fern, etc might be options.>
Thanks.
Sal F.
P.S. On another note, I know that the Pangasius catfish will grow huge.
<Huge is an understatement!>
It's already grown like gang busters to four inches very quickly. (the big chain pet store description said 6" max [wrong!]). I already have a store that will adopt it when it outgrows my tank.
<Good. While the 1.3 metre specimens aren't common in aquaria, Pangasius hypophthalmus easily get to 60 cm+ under aquarium conditions. Lovely fish if you have the space, but they're schooling, nervous fish that easily damage themselves when kept singly, particularly often damaging, even losing, their eyes. So be realistic about when it needs to go; I'd say that once it tops 15 cm/6 inches, it's too big for a 55 gallon system. Cheers, Neale.>

Big community tanks (filtration; stocking); Serrasalminae (behaviour, compat.) 8/18/08
Hello There,
I have been reading over and over your website for close to 4 years now, and I can't tell you how wonderful you guys are at educating people... and for free... This will be my first post to you and I just want to be sure on what I am getting into next. But more praise first... One could probably earn the equivalency of a masters degree in aquatic biology from the information accumulated here along with references of others... If only we could study major after major... Doubling in Sociology and Music performance took up a bit too much of my time to consider anything else, and what a shame!
<Ah, your education doesn't end when you graduate! I've known people who've published in the scientific press despite their science being a hobby: their day jobs were completely different!>
A little about me: I have worked at 2 different aquatics related businesses in the past and have been steeped in the hobby for about 20 years now. I maintain 4 aquariums; a 75 gallon mixed species rainbow fish and gudgeon biotope (river rock, driftwood, Vallisneria nana [where might I find some v. caulescens?], sand), a planted 125 gallon with a quintet of (Peruvian) Rio nanay wild discus cha ching!!!, a school of black morpho tetras (Poecilocharax weitzmani... [once one understands Latin vowels it's not so difficult he-he.]), some cories, 2 Farlowellas and a pair of ramirezi, some nice chunky driftwood, peat/sand substrate, and sword plants (e. tenellus, e. ozelot, and e. bleheri, with a bed of jungle Val), an iwagumi style 30 gallon with Kuhli loaches, celestial pearl Danios (trying to breed them) and an SAE, plants include blyxa japonica, Hemianthius calichitroides, and Rotala wallichi. And finally a 20 gallon low tech crypt tank with only crystal red
shrimp. Maybe a Betta bowl/java moss :-). I use Eheim filtration and t5 lighting on all these systems, I conserve rainwater, and supplement that with R.O. during dry times along with my additives. I go through lots of water... So, I will quit my introductory rambling for now.
<Well, does sound as if you've kept more fish than me...>
I have just purchased a 300 (6"lx36"w25"h) gallon glass tank, and I am in the process of building my stand (and wreaking havoc on my basement). (4x4 hardwood beams framed with 2 x 4s on each side w/ plenty of bracing) and filtration system. My question is about my entire filtration idea, as I have not ever tried to maintain a system this large, I bought this tank used in great condition, and I am too afraid to attempt drilling it and installing an overflow. So, I am using an overflow box with 2 U tubes. Water will be prefiltered and run through carbon bags in the outflow box. My sump is going to be a chambered 75 gallon aquarium; first through filter pads then into a chamber overflowed onto a drip plate. Then the water will drip into a chamber with bio-balls atop egg crate with air stones underneath. This will be overflowed into a vegetable chamber, [what is the best plant I may use here for nutrient export?
<Most anything floating and fast growing. Floating because it's closer to the light, and fast growing because that's where the nitrate/phosphate goes. This said, freshwater fish are generally fairly tolerant of nitrate, and water changes are comparatively inexpensive compared with marine systems. So I'd tend to view plants more as tools for algae control than water purification. Mind you, "vegetable filters" have been done, and I'd direct you to the book 'Dynamic Aquaria' for a scientific review of the subject.>
I was thinking a larger type of Vallisneria or Watersprite, although I have read that emergent plants may be even better... I am just not too familiar with this...]
<Emergent plants receive even more light than floating plants, hence growth rate is even more rapid. Hygrophila polysperma and especially Hygrophila corymbosa for example do very well like this, and growth of both species is astonishing if they're getting natural sunlight or intense artificial light.>
Then water will be run through another filter pad, through another drip plate and pumped back into the display. I am going for around 1500 gph with the return pump here. Also, I am going to run 2 emperor 400's on the display to help out with large waste that might not be overflowed. I'd really like your take on this idea.
<For reasons I've discussed here many, many times I don't think much of hang-on-the-back filters. Advanced aquarists certainly shouldn't be looking at them. In short, I don't like the fact the inlet and outlet are close together; I don't like the very poor mechanical filtration characteristics; I don't like the fact you're "locked" into using proprietary filter modules such as useless carbon and Zeolite. Infinitely better to use a standard canister filter, internal or external, depending on your tastes (external canister filters being better value but less easy to maintain). If you're keeping a bunch of big fish, it would be insane to go with some Chinese-made hang-on-the-back filter, and you'd be better off investing in a super-reliable Eheim filter that will keep these messy, sensitive fish in good health. Eheim make some great "pro" filters if you're deep of pocket; otherwise multiple "classic" filters like the 2217 will provide a good value alternative. With big fish, you're after 8-10 times the volume of the tank in turnover per hour. Arrange the inlet pipes and spray bars all around the tank to produce strong current working all the way around the tank.>
This tank is going to house, for now, 6 3" cichlid orinocensis( I want a pair, and I plan to sell the rest once I grow them),
<Nice fish.>
some rotkeil Severums,
<Gorgeous fish: marine quality colours, if you can get some decent stock.>
a royal Pleco (L-190). a goldy sunshine Pleco (L-014)
<Do not underestimate the territoriality of large Plecs. Also Panaque spp. MUST eat wood, and they produce masses of chippings in the process. Hang-on-the-back filters will be totally overwhelmed and simply won't remove the woody debris from the substrate, lacking the "suction" required. Again, canisters are the way to go, ideally combined with a reverse flow undergravel.>
and maybe a tigrinus catfish if I can find one small enough and in an acceptable price range.
<A "small" Tigrinus? No such beast. Adults quickly get to 45-60 cm. Not tolerant of other catfish and markedly territorial. Would perhaps recommend slightly smaller, more easy going species like the excellent gregarious species Sorubim lima. But given you have 300 US gallons to work with, you should find lots of options in the 30-45 cm range that will work in this community. But do always remember big catfish not only demand good water quality but also put a huge strain on the filtration system. Before spending any money on big cats, it's always worth balancing the impressiveness of a catfish in a photo with the fact many species hide away all the time and get pretty boring. Since you're stuck with a big catfish for something like 20 years, you may as well choose a species that is entertaining!>
Nothing is in it now, so my options are open, I have already got the ball rolling on the peacocks as soon as the tank is cycled they are a definite.
<OK.>
One more question and I'll get out of your hair, he-he. I ventured to the public aquarium close to my home in Chattanooga, TN a couple weeks ago, and I noticed that they are housing their peacock bass with piranha species. the tank is not too humongously big and it seems fairly crowded.
<Do remember their may be water capacity out of view, so the size of the tank you SEE can be misleading in terms of water volume. In any case, public aquaria have the luxury of moving fish around from one big tank to another, or even selling on unwanted livestock, and that's something you may not be able to do.>
I don't understand how they can do this in captivity without major major aggression, the peacocks and piranha both have amazing color and all seemed to be in decent finnage.
<Cichla and Serrasalminae have a complex relationship in the wild. Adults of each species compete for the same resources, but there's more to it than that. Many piranhas feed on the fins of large fish, and Cichla have evolved behavioural characteristics that allow them minimise such attacks. Furthermore, the eyespot is believe to be a way to confuse fin-eating fish. Conversely, adult Cichla eat juvenile piranhas. What these all means for aquarium maintenance I couldn't say, but it's interesting to speculate that a "stand off" might exist where specimens of similar size were kept together. How stable that would be in the long term or within the confines of a home aquarium is up for debate though.>
Everything I have read about piranha has warned they should only be kept as a solitary species,
<Does depend on the species: some are gregarious at certain times of the year, and only become markedly territorial when breeding. The size of the school makes a HUGE difference, and that's where aquarists come a-cropper. It's really a case of the more, the better, and successful displays in public aquaria often include dozens of specimens. Hobbyists often try with five or six fish, and end up with just the one male at the end.>
and for some more aggressive species only as solitary animals I would like to know about how they achieve this... I took a behind the scenes tour with a great friend of mine, even got to see young weedy sea dragons that were hatched there at the facility, but most of the questions in regards to husbandry I had, the guide couldn't answer. Although, being feeding those massive sand tiger sharks and the green sea turtles was well worth the extra money.
<I'm not a huge piranha fan, and consider them among the least exciting fish in the hobby. That said, if you're prepared to keep 10+ species of Serrasalmus spp. of moderate size, you can get lucky and create a stable group. Experienced keepers tell me the very small specimens (coin-sized) you see in shops are often much more nippy than the sub-adults, so one mistake is buying a bunch of babies hoping to rear them together. While that approach works with many fish, apparently it doesn't with Serrasalminae. For most aquarists, Exodon paradoxus is a much better piranha-like fish for maintenance in groups. It's smaller, forms stable schools more readily when kept in large numbers, and is far prettier (in my opinion). Does the same feeding frenzy thing, but eats anything, so can be easily maintained on chopped seafood. I'll also make the point that there seems to be a relationship between aggression and the use of live foods. Fish fed dead/frozen foods are consistently less aggressive than ones fed live foods. Unfortunately many people who buy piranhas choose to feed them live animals, particularly goldfish, and apart from being a death warrant in terms of healthcare, that habit likely makes maintaining a stable school less easy.>
Hope you have a good one,
Adam
<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 jardini. 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... Im 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.

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 Im 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? Im 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 gonna 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 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.>

Guppies tails being eaten – 07/01/07
Hi,
we have a 60 litre tank with several tetras, 2 Silver Dollars, 6 Platys (with a week-old baby in a net cage!) & one Clown Loach. A few days ago we acquired 4 Guppies which we assumed to be male due to their colourful tails. All was fine for the first 2 or three days then, one morning, we found a severely traumatised little person minus tail! We quickly separated him from the others but he died shortly after. We noticed that one of the other Guppy's tails had been nibbled, though not to a great degree, and kept an eye throughout the day. However, yesterday morning, he too had died. Whatever's happening seems to be doing so during the night. Might you be able to advise as we find it so distressing & feel we've done something awfully wrong. Many thanks, Don & Jenny.
<Greetings. As you perhaps realise, a 60 litre (16 US gallon) tank is too small for silver dollars. Silver dollars potentially over 10 cm (4") in length and are exceptionally active and fast moving. I'd hesitate to recommend them even for a tank two or three times the size of yours. Clown loaches are schooling fish, and should be kept in at least a trio. Keeping a single specimen isn't very fair to the fish, and you'll probably find it is shy and nervous. Clown loaches are even bigger than silver dollars, and definitely need a bigger tank than yours. For a trio, even a 200 litre tank would be too small. So that's the analysis of your livestock over! Almost certainly the guppies are being nipped by the tetras. Silver dollars generally aren't nippers, so I'd cross those one of the list. But serpae tetras, black widow tetras, flame tetras, and a few others are regularly implicated. So if you let me know which tetras you have, we can try and identify the culprit. In some cases the problem is too few members of the school, but in other cases the tetra concerned feeds on skin and scales in the wild, so is simply doing what comes natural. Either way, mixing tetras and fancy guppies is almost never a good idea. Even Neons have been known to nip fins under such circumstances! In the meantime, treat for Finrot/fungus. Cheers, Neale.>

Reply... Neale, Don & Jenny... Silver Dollars... 7/2/07
Hi Neale,
many thanks for your reply and advice. Our Silver Dollars are about 3-4 inches and seem quite happy. Our Clown Roach 2-3 inches & also seems happy. He/ she is out and about quite a lot from under his log. We intend getting another as we had 2 to start with but one vanished overnight some weeks ago!- but haven't been able to locate a small one. We have a few Neon tetras, 5 Leopards and 4 Blue. Our one remaining Guppy seems unscathed and absolutely fine! Is it possible he might be responsible for the de-finning and ultimate demise of his three amigos?
As you've probably surmised, we are novice fish enthusiasts, having started keeping fish at the end of March. Most of our purchases ( Tetras, Platys and, more recently, our unfortunate Guppies) have been the result of advice given by a Fish Specialist shop in Rhyl from whom we also bought our tank & equipment. We have already decided to get a second tank. Ta muchly, Don & Jenny
<Hello Don & Jenny! Guppies can be nippy towards one another. Males are aggressive, especially when kept in small groups without females. Whether to the point of killing each other I cannot say. Never heard of that. Possible though. I have no idea what "leopard" tetras are. Never heard of them. Do you mean Leopard Danios? Small, minnow-like fish with spotted bodies that swim blazingly fast? Danios can be pugnacious, and tend to be fairly high energy animals. Work best in groups of 6 or more; any fewer and they often harass their tankmates, not out of malice really, but simply frustration, and the need to chase things and burn off some energy. Blue Tetras are fairly uncommon and I don't have personal experience, but they're said to be peaceful. Neons are not normally nippy but they have been know to bite Siamese fighting fish, so the possibility of nipping a fancy guppy definitely exists. As for questions of "happiness", there's two kinds of happy. There's what works now, and then there's what works in the long term. Your fish quite probably are happy know because they're young. Fish are often adaptable animals and will thrive in less than perfect conditions. But clown loaches and Silver Dollars get big and live for 10+ years, so long term you need a plan. I'd recommend keeping an eye out over the next 6-12 months for a bigger aquarium. There's nothing more miserable than a big clown loach by itself wedged into a too-small aquarium. Clown loaches are notoriously sensitive, sometimes making suicidal jumps out of aquaria when they feel stressed and other times getting whitespot very easily. Clown loaches are "allergic" to most standard medications, as I trust your retailer told you, and you must never use things like anti-whitespot potion in a tank with clown loaches. Hope this helps, Neale>

Bacterial Hemorrhagic Septicemia / fin and tail rot 6/30/07
Hello,
<Hi there>
I have a 16 year old Silver Dollar that has the following conditions. Left pectoral fin is gone; the flap is there and flaps like crazy, but there is no fin attached.
<Mmmm, might grow back if not too far gone...>
Both pelvic fins are completely gone. The caudal fin is badly frayed (3 weeks ago was almost completely gone) and is strangely red at the base close to the fish body.
<Something amiss here...>
History; up until 6 weeks or so ago, I had the silver dollar in the tank with a Pacu.
<Ohhh>
The Pacu was huge and out sized the dollar by ten times at least. One day I noticed that the silver dollar was missing most of its caudal fin and what was there was badly frayed. The pelvic fins were gone as well as was the pectoral. I assumed it was fin and tail rot and treated the tank with Mardel Maracyn Two. The caudal fin began to get better for about a week then went to worse again.
<... stress, bullying...>
I then thought that it was the Pacu. Although the Pacu never picked on the dollar in my presence I thought it was happening when I was not around. I wanted to get rid of the Pacu any way since it was so big and messy to take care of. I found a home for the Pacu at a LFS adoption tank and that left my dollar to her self. The caudal fin healed from almost nothing to about one-half but then quit and will not heal further. The other fins have not changed at all. I am patient and though that in time all would be well again so went out and bought 3 more silver dollars to keep the old one company.
Before getting the new dollars the old one ate well, but now the feeding frenzy and competition is causing the old dollar to swim faster to get her share, but with out the control of all her rudders she cannot aim correctly at the food and misses it.
<Provide more bulky food items... greenery that the impaired one can eat easily... Like blanched zucchini>
Also, she cannot maneuver well enough to keep up with the other dollars who are younger and smaller. This is causing me to revisit medication or some form of treatment before the dollar winds up dying.
<... Medication not advised here>
My tank is 75 gallon, Ph - 6.8, nitrite - 0, ammonia - 0, Nitrate 20-40, GH 3d, KH <1d, total dissolved solids 300ppm, RO water conditioned with Kent RO right,
<I'd use less, let the TDS hover around 100 ppm>
Ph buffered with Kent Ph 6 and 7 (phosphates), and the temp is 25.5c.
My 1st question is this- I read that the redness near the base of the fins could be Bacterial Hemorrhagic Septicemia. Does it sound like it to you?
<This... is a condition... Need to seek out, address root cause/s... the trauma, "dirtiness" from the Colossoma... Takes time to heal...>
2nd, Can the pectoral and pelvic fins come back if I treat the fish correctly, or are they gone for good?
<Can regenerate>
3rd, what/how would you recommend treating the condition(s) with and should the treatment be carried out in a separate tank, or is the condition contagious, requiring that the entire tank be treated.
Many thanks!
Scott S


Re: Bacterial Hemorrhagic Septicemia / fin and tail rot 6/30/07
Hi Bob,
Thanks for the quick reply.
<Welcome!>
I'll take your advice and not medicate.
How do I lower the TDS?
<Mmm, either start with "cleaner" water or not add to it...>
I add chemicals when I do water changes as follows.
To 15 gal I add 1.5 tsp Kent RO Right,
<Leave most of this out... this should do it>
1 tsp Kent Ph Precise 6.0, 0.5 tsp Ph Precise 7.0, and 15ml Tetra Black Water Extract. That brings my TDS in the new water to 235. Still even then my GH is very low, between 2-3 dH, and the KH is so low I cannot measure it.
Would you add different quantities/products?
Thanks again,
SL
<Try cutting back on the RO product... try a level teaspoon of baking soda (Sodium bicarbonate) instead...>

Re: Bacterial Hemorrhagic Septicemia / fin and tail rot, Silver dollar... 6/30/07
Hi Bob,
You must have forgotten that I am using RO water, or I doubt that you would recommend that I only add 1 tsp of baking soda to 15 gal of it.

On the label of the RO Right, it recommends 1 tsp per 10 gal for soft water. That is what I am currently adding. Also, on the Ph Precise I am following the label as well.
Since my fish has out-lived my dog, I must be doing something right with respect to water chemistry and husbandry.
<... what is your point?>
My quandary is in treating an old fish which has lost much of its finnage, and over an 8 week period has not shown much improvement despite a great deal of effort.
Your suggestion of more bulky food was a good one. The silver dollar seems to really like green beans, and since none of the other dollars pay any attention to them, the wounded one has them to herself and once again has a full belly.
Also, I have taken your advice on supplementing vitamins. I have no experience with mixing food, so I am adding freshwater essentials to the water to add vitamins. Hope this works in lieu of.
Thanks for your help,
SL
<Please... just use the indices, search tool. RMF>

Re: Bacterial Hemorrhagic Septicemia / fin and tail rot – 07/01/07
Bob,
<SSL>
What is my point you ask? Most of what I do with respect to maintaining my fish tank is based on information gleaned from posts on your web site and from your direct responses to my previous questions over the past 2 years.
I.e., RO water instead of tap, frequent water changes, softer water, discontinuing fish-slime additives, etc.

Then, in this most recent volley of correspondence you suggest that I go to pure RO water without any additive other than baking soda
<Sorry for the lack of clarity... I would try decreasing the RO Right product by half ml.s per time/maintenance interval, and in addition, add the level tsp. of bicarb>
which would leave my tank with out any major or minor elements, no GH, and enough alkalinity to bring my Ph back up to 8.0. Why would you suggest this? It makes no sense to me in light of the other comments and suggestion on your site.
SL
<Do try this in a separate container... and measure the resultant chemistry... a day later. B>

Parasitized Metynnis - 06/27/07
Hello, Wet Ones!
<In England, "Wet Ones" are moist towel things used to wipe babies' bottoms when changing their nappies (diapers). So, not normally something you call someone.>
I have a silver dollar, Metynnis argenteus, that I think is parasitized. He was in quarantine (30 gal w/ air stones and Whisper III OTB filter) for 2 months, along with several rainbows, some hatchet fish, and some neon tetras. All appeared well in quarantine. We moved these fish to our 150 gal show tank about 4 weeks ago. After about 3 days we lost one of the hatchet fish to causes unknown. Four days ago we noticed a whitish spot on the side of the silver dollar and a similar one on one of the hatchets. The hatchet passed the next day. The silver dollar is still feeding well and swimming just fine! The white spot is diminished, but this dark spot just showed up. I've included three pictures. What is it!!!
<Well, I can't see anything particularly worrying in the photo. Treating the tank with anti-whitespot would probably be wise though, just in case. Hatchetfish are uncommonly sensitive fish, especially when recently imported. Once settled, they become a bit more robust, but the smaller species (Carnegiella spp.) never really become "hardy". Do bear in mind hatchets seem to need a lot of food to stay healthy, while silver dollars require at least some greens in their diet. Observing these two guidelines should help in the long term.>
Branon
<Cheers, Neale>

hi.
<Hello!>
my oldest silver dollar has gone mad! - 6/7/07
<Oh dear.>
he swims frantically around our tank & has hurt himself badly
<Odd. Usually, this means the fish is unhappy for some reason. Can be water quality, but other factors to consider are: Noises (such as loud TVs or doors banging). Aggressive tankmates. Fin-nippers.>
he has taken off his lips & fore head
<Not sure what you mean by this. Is he damaged? If so, treat with anti-Finrot/anti-fungus medication to stop things becoming septic.>
he does it at least twice a day
<Try and establish if there is a routine. Are there children banging around the house when this happens? Characins are very sensitive to vibrations and sound. These are open water fish, and their response to alarm is to swim rapidly away from danger. In the confines of an aquarium, this can cause problems.>
what's wrong with him?
<No idea. Does he have friends of his own species? Silver dollars are very sociable, and won't really settled down if kept alone. A group of 6 or more is best.>
our tank is huge & all checks are fine
<Define "huge". At the very least, check there is plenty of swimming space and strong water current.>
what do we do?
<Not sure. How many silver dollars? What are the tankmates? How big is the aquarium?>
thanks Donna
<Cheers, Neale>

Re: silver dollar has gone mad! - 6/7/07
We have 3 silver dollars. His original friends died of old age. His new friends are only about 6 months old (had them about 3) but this behavior is new only about 2 weeks that he been acting weird, he took to the new babies straight away & hangs around with them all the time.
<Very good.>
Our tank is a huge corner one & we have a few female guppies & black & red shark & 2 Plecs. They have all lived happy for ages. The Water is clean, with filter & pump. He is about 7-9 years old & I have noticed him 'jump' before when i turned the hoover on but in the past 2 weeks he has started dashing around our tank for no reason, he has hurt himself now.
<Very odd indeed. He's a fair age though, so you've obviously been looking after him pretty well.>
all the skin is missing from his lips & forehead. we are worried now & we don't know whether it is better to put him out of his misery. he's like one of the family though, we've had him years.
<If he's otherwise fine, schooling with his pals and eating properly, then I personally wouldn't destroy him. I'd treat the tank with anti-Finrot/anti-fungus so that his skin heals properly. You could also add some Melafix as well. Give things a few weeks to see if he settles down. You might want to remove anything rough and spiky in the aquarium, just to make sure he can't damage himself further. You could also add some cheap floating plants, such as hornwort or Canadian pondweed, to see if the extra shade helps him settle down. A lot of fish enjoy floating plants. If things still don't improve in 3-4 weeks, then maybe then you might need to destroy him.>
please help us
thanks
Donna
<Cheers, Neale>

Silver Dollar Tetras 5/10/07
Hello was looking at your site under Characins, the two silver dollars, Myleus schomburgkii and M. rubripinnis are listed under other sites as reaching 39 cm long. Yours were juveniles then?
< Probably close to adult size.>
, anyway my question was the teeth. Do they bite your hand if you put it in the aquarium, do they attack other fish, harm them?
< They usually attack plants. We use to call them plant piranhas. If they think that your hand is food then they will take a nip. This usually happens when people are trying to feed them by hand. The bites do no damage to the best of my recollection.>
I know about the common smaller silver dollar M. hypsauchen do they also have sharp teeth but don't use them? I'm trying to figure out if I can put these larger silver dollars into a big aquarium with Tinfoils, balsa, one Oscar.
< Silver dollars make a fine dither fish for med to large community tanks. Just remember that they love to eat plants and need some plant material in their diet.-Chuck>

Pacu Diet 2/14/07
Hey there,
<Hey back...>
I have a couple questions.
<Ok....>
I have two red belly Pacu one doesn't eat what
mite be wrong with him.
<A multitude of things could be wrong/not wrong with him, fish go through hunger strikes for various different reasons.>
Another question is I feed my Pacu algae wafers what
are some other good foods for juvenile Pacu?
<Well you are on the right track, although they look vaguely sinister like their cousins (you know the one), Pacu's teeth are built for the consumption of vegetable matter...and only every once and a awhile consume protein/animal matter, usually insect/bugs. For smaller specimens algae, wafers, Nori and flake food consisting of Spirulina would be my choice. Adults are a rare exception, usually when talking about aquarium animals I usually recommend staying away from terrestrial vegetable but n this case...it may be okay. (In fact one of the neatest things I have ever seen is an adult PACU chowing down on a large cucumber)...as for the PACU itself I will spare you the lecture on it's adult size and make a leap of faith assuming you have researched it's adult size and needs.>
Thank you for all the help.
<Of course, Adam J.>

Silver Dollar dis.? 10/4/06
I have read several of your pages on fish diseases and still have some questions.
<Me too>
I have a 25 gallon tank which I recently had to drain due to a leak in the top. I moved all of my fish temporarily into a smaller tank. I used water drained from my 25 gallon and one of the same filters hoping not to stress anyone too majorly.
<Good>
I have a 6yr old Silver Dollar about 4inches and 2 smaller ones. I have 4 Black Skirt Tetra, 3 Rasboras, 2 algae eaters and 2 Longfin zebra Danios. Everyone seemed fine except the Silver Dollar who seemed to develop a lump on his side which now resembles a small air bubble.
<Likely resultant from a physical injury in the move>
His tail fin and upper fin then appeared to be torn badly.
<Ditto>
 I treated the tank with Maracyn and Maracide, as well as Stress coat. The fins seemed to repair themselves a bit and the swelling on his side went down a little.
<Takes time>
Then I noticed a small white spot on his upper fin and have started treating the tank again. This time with Maracyn TC. I have done frequent water changes. My ammonia, nitrite and nitrate levels are fine.
<Thus far... do monitor ammonia... the Tetracycline can/will kill off your nitrifiers>
This fish eats as well as it ever did. I would hate to lose him if there is something I can do to save him Any help you can give is greatly appreciated.
Thanks, Sandy
<Mmm, the best thing would be to repair (Silastic) the larger tank, move all back there, and wait and see. Should self-repair with good water quality, time going by. Bob Fenner>

Re: Silver Dollar 10/5/06
Thanks so much for the response. I did forget to mention everyone is back at home in the larger tank. No more leaks..... Now hopefully I can let nature do it's thing, and not over react at ever little spot.....for my fishes sake.
Thanks again +)
<Ah, yes. Welcome. BobF>

Temperature Range - Metynnis and Rams? Sys., comp. - 09/30/2006
Hello y'all,
<Hi. My apologies for the delay in reply; I've been out, and your email came to us in a format that unfortunately our Webmail system had some trouble with, and I am one of the only folks able to respond to it.>
First of all, thanks as usual for your maintenance of a wonderfully informative site.
<Thank you very much for these kind words.>
(I recently wrote my comprehensive exams for a PhD in education, and cited this site as a great example of a constructivist learning environment. So thanks for your contribution to my degree as well.)
<This is high praise indeed - thank you again.>
I would like to keep Metynnis hypsauchen and Microgeophagus ramirezi together in a 150 gallon system.
<Maybe possible in this size system, given enough plants and hiding spaces.... but do keep in mind that the rapid schooling and darting about of the Metynnis may be stressful to the shy rams. This is something I, personally, wouldn't try, but I imagine it can be done with success in as large a system as this.>
My plan is to keep the temp at about 80-81° F, as this seems to be at the upper limit of the silver dollars and the lower limit of the rams.
<The rams can go lower if you don't intend to breed. Warmer would be preferable for them, but I'm rather concerned about the warm water making the Metynnis even MORE quick and spazzy.>
However, I'm concerned that much of the literature about rams stresses that they're delicate, and happier at temps around 85.
<Indeed. But I would not bring the Metynnis to this temperature.>
Should I:
a) go with the "intersection" temp of 80-81
b) keep the temp higher, on the theory that the silver dollars are more tolerant of out-of-range temps than the rams
c) not keep the two species together?
<.... I would choose "C". But again, that's just me.>
Thanks again for your help and patience.
<And you, again, for your kind words and consideration!>
Melinda Johansson
<All the best to you, -Sabrina>

Tom... need titles to find/match prev. corr... 9/28/06 ? Pacus, Serrasalmine IDs...
Tom,
<<Hi, Lisa.>>
Oh, I’m so confused! Well, my cousin said that I had a cichlid? I know for sure that I had at least one I know for sure is a silver dollar. . . ( I had two) But maybe it’s a Pacu?
<<Could be... These two, and Piranhas, are sometimes confused at the juvenile stage. As they mature, the differences become more obvious.>>
Is there any kind of difference between a Pacu and a Silver Dollar?
<<Oh, Lord, yes! Sorry about the emphasis but if you have a Pacu as opposed to a Silver Dollar, you'll need a 300-gallon aquarium to keep it. Not likely, I'm thinking. :) Now, a Piranha might have a distinct taste for your other fish.>>
I know for a fact it was eating my fish because one day I saw parts of what was left of my fish chomping on it! I really did get the memo.. Just its wrong.. ( haha) Yes, its very ‘nervous’ I can’t even turn on the light in the tank and it goes crazy.
<<Again, this is common of Pacus, which is why they fall into the "tank buster" category. They can/will "frenzy" themselves into anything and everything in the tank. Not what you want in a fish that reaches 30+ inches in length and can weigh upwards of 55 lbs. or more.>>
My fish is not typical in any way. Oh, I think this is kind of funny. When I was cleaning my tank I noticed my fake plant had gnawing marks all over them. I wonder who that was from…
<<Silver Dollars and Pacus, both, will eat aquarium plants of just about any variety. (There are some plants that folks have found that won't get devoured but most of those that you'll find readily at the fish store will be turned into "lunch" sooner or later.)>>
Okay for the filters… even if you have charcoal, they don’t get the bad stuff out- thought it got the ‘invisible solids’ out?
<<Activated carbon does a very nice job of "polishing" the water of hard-to-eliminate solids but does nothing for ammonia and nitrites.>>
Um, I usually clean the filter when it gets kind of bad. Hard to get the stuff out, I change it. I’m such a bad fish keeper! Definitely getting an F… (haha) I'm guessing you are an aquarist yourself?
<<Yes, indeed.>>
If so fresh or saltwater?
<<Strictly freshwater at this point in time, Lisa.>>
Yes, I do wish there was more time in the day. That would be nice… Lately I been going to bed kind of early 9-10. I guess my body isn’t in the swing of school yet. Should I tell the person about the worms? Or keep and eye out on the tank? ( I’m scared to tell him.)
<<As I suggested, Lisa, the problem is with the tank, not the fish. If your friend's tank comes down with Planaria, it will be due to water conditions in his aquarium, not the fish you gave him. You're off the hook! :)>>
I’m sorry I’m bombarding with a lot of questions.
Thanks, Lisa
<<Any time, Lisa. Tom>>

Red Hooked Metynnis 6/8/06
I have 3 large red hooked Metynnis. The old guy or girl has been with me about 20 years.
<How nice! Myleus are faves of mine>
I feed them a diet of green beans, bananas, lettuce and Hikari Cichlid Gold medium pellets. I know this is a long time for a fish to live but just how long have these type of fish been known to live. If you have time please give a response to me question.
Thanks so much Jean Smith


Re: Red Hooked Metynnis 6/9/06
Thanks so much for your reply. I have mine in a 55 gal tank. As I said I have the old one, and one that is about l0 years old and a juvenile that I have had about 5 years. The old ones hook has lost some of the red and it seems to me that his red color has faded some. I keep hoping that they might spawn.
<Would likely need more room...>
Also I have two small ones that I bought last year. Thy do have big teeth The two older ones have brown and black markings on them but the young one is still silver. They are kind of crazy sometimes running into the tank and hurting their noses.
<Mmm, again... need bigger quarters>
 I just love them! Again thanks for your reply. Jean
<Thank you for sharing. Bob Fenner>

Silver Dollar Getting Pretty Old - 09/13/06
Have you ever heard of a silver dollar fish living as long as 40 years??
< That's an old fish.>
I have one and has Popeye only in one eye. I have had this since 1976 and was given to me by someone that claimed to have had this fish for 10 years before me.
What is the lifespan of a silver dollar it must be more than 7 years??
< Sounds like you have the record.>
I must hold the Genius book of records with this fish. The fish developed Popeye over a month ago. I have tried fungus medicine and tetracycline but neither seems to help? Haven't tried the Epsom salts yet. Please advise.
< Do a 50% water change, vacuum the gravel and clean the filter. Treat with Metronidazole and Nitrofuranace in a hospital tank if you can. If you can't find the medications then try Clout.-Chuck>

Red Hooked Metynnis 6/8/06
I have 3 large red hooked Metynnis. The old guy or girl has been with me about 20 years.
<How nice! Myleus are faves of mine>
I feed them a diet of green beans, bananas, lettuce and Hikari Cichlid Gold medium pellets. I know this is a long time for a fish to live but just how long have these type of fish been known to live. If you have time please give a response to me question.
Thanks so much Jean Smith


Re: Red Hooked Metynnis 6/9/06
Thanks so much for your reply. I have mine in a 55 gal tank. As I said I have the old one, and one that is about l0 years old and a juvenile that I have had about 5 years. The old ones hook has lost some of the red and it seems to me that his red color has faded some. I keep hoping that they might spawn.
<Would likely need more room...>
Also I have two small ones that I bought last year. Thy do have big teeth The two older ones have brown and black markings on them but the young one is still silver. They are kind of crazy sometimes running into the tank and hurting their noses.
<Mmm, again... need bigger quarters>
 I just love them! Again thanks for your reply. Jean
<Thank you for sharing. Bob Fenner>

Silver Dollar with one cloudy eye 6/6/06
Hello Crew
<Jasmine>
One of my Silver Dollars (I have 5 in total) has one cloudy eye. Water seems to be fine (ammonia=0, nitrite=0, nitrate=10ppm).
Being on one eye only, what could be the cause? Is it bacterial or a result of an injury?
Thanks
Jasmine
<Most likely originally the latter, possibly secondarily the former... If this is just "new" I would hold off on actual "treatment"... In all likelihood it will cure of its own accord. Bob Fenner>

Hatchetfish, Silver Dollars, Discus, Compatibility - 05/19/2006
Can one keep Hatchet Fish, Silver Dollar, and a few Discus fish in a 55 gallon tank?
<I would not mix silver dollars and discus. Discus are typically shy and timid, silver dollars are boisterous and perhaps too fast/aggressive. The discus would likely not get enough to eat in this mix, and would get pretty stressed out.>
What do I need for setup if possible?
<Research, mostly. http://www.wetwebmedia.com/FWSubWebIndex/fwsetupindex.htm >
pH? Ammonia? Nitrate?
< http://www.wetwebmedia.com/FWSubWebIndex/fwestcycling.htm , http://www.wetwebmedia.com/FWSubWebIndex/fwph,alk.htm >
No plants if possible. Thanks -Mark
<Wishing you well, -Sabrina>

Fishy Mystery From A Forum Reader - 03/08/2006
I got your email address off the WetWeb website. I have a question and am not a member.
<Feel free to join the forums; it's free and fun!>
I have 3 silver dollars, I have a 47 gallon tank with a few platies, mollies and tetras. I had a 5 inch rainbow shark and he disappeared as do some of my platies and mollies from time to time. I think when my fish die the other fish eating the body, as sometimes when I clean my tank I'll find something that looks like a skull or fish skin. The man at the fish store said silver dollars are aggressive, I've never read anything bad on the internet about silver dollars. What do you think?
<About what, the silver dollars? Or the mysterious disappearances? Silver dollars CAN be aggressive. I very much doubt, though, that they'd be able to take out a sizeable critter like your rainbow shark minnow. They tend to be a little harsher on plants than fish, but smaller guys like little platies and tetras may get munched. As for the dying fish, yeah, it is VERY common for active, healthy fish to try to eat a dead or dying tankmate, so that's what's happening with the bodies - the mystery is, what exactly is killing them? The answer here may be something in terms of water quality. Please be testing ammonia, nitrite, and nitrate; ammonia and nitrite must be ZERO at all times; nitrate less than 20ppm. If this is not the case, correct it by doing water changes until the levels are right. Make sure you use a chlorine/chloramine neutralizer and match the temperature and pH to that of the tank. Wishing you well, -Sabrina>

Healthy diet for a Pacu 1/4/06
Hello, my name is Brian and I have a Pacu that is growing ever so quickly.
<Heee, well-kept ones do>
 I need some help with a healthy diet for my Pacu. Right now the Pacu shares a 38 gallon tank with a Pleco. I feed the Pacu cichlid sticks and algae wafers.
<Good choices>
I would like to start feeding him more home-based foods such as spinach, carrots, and other veggies that you may recommend to supplement the cichlid sticks. It seems that the Pacu is growing at an extremely fast rate. Hopefully the change of diet might slow it down. Any and all help is deeply appreciated. -Brian-
<A routine of "blanching" such terrestrial-based greens... what you list and pretty much any others that are solid, by microwaving or boiling for a minute or two on the stove... and allowing to cool is about all that is required here. Do be aware that there is a "learning curve" here... for the Pacu to understand what is food, how to eat it. And that these foods call for more water changes, filter cleaning... Bob Fenner>

Piranhas…still illegal in California 12/9/05
Hi
<Hello.>
Just wanted to know if you know anybody selling the piranha I'm trying to locate but still having a hard time to find one. I live here in California.
<Ahh…bingo, all species of piranha are illegal in our Golden State here…both to sell and own. But on the bright side you can’t beat the weather here. I’m enjoying this 65 degree winter.>
and really wanted to get the red. Pls send any info at XXXX@X.XXX
<Sorry I could not be of more help, Adam J.>
<<Be smart, go with Pacu. They look a lot like piranha, are nowhere nearly as difficult to keep, and are fun to feed big bugs to. Marina>>

Silver Dollars, Environmental Disease - 10/12/05
My silver dollar fish have had on-going fungus that I can't get rid of. It eats up their fins and spreads across their body. I have tried all different Meds for this, and have since stopped treating them to keep from poisoning the tank with many different Meds. The various Meds would seem to cure the fungus, but it comes right back when I stop treating them.

I have a 55 Gal with 5 fairly large silver dollars, 4 fairly large angels, 2 clown Plecos, and 2 neon tetras with a knack for survival.
<Tooo many big fish for this tank.>
My water is very hard and I've been using peat moss to soften it in a storage container. I'm concerned because my nitrate level has climbed quite high (160),
<Disturbing, and toxic if not deadly at this level.>
hardness was at 115ppm, ph 7.6, ammonia=0 and nitrite=0. The submersible transfer pump from the storage tank is turned off until I'm ready to transfer water to the fish tank, I first run the water for a short time to clear the pump of the standing water in the pump and tubes so as to run only fresh water into the tank. The storage tank is circulated by an external Emperor filter that I put the peat into. The peat I bought at a Lowe's garden department, doesn't list any additives that I thought would add to Nitrate increase. The 55 Gal. fish tank also uses an Emperor filter for general filtration (but no peat added), and an undergravel filter.
<Consider removing the undergravel filtration - often this is a MAJOR contributor to very high nitrate due to accumulated organic material under the filter plate(s).>
All the fish seem to be doing ok except for the silver dollars, although I'm guessing they all may be uncomfortable with the high nitrate level.
<Yes, this level is absolutely staggering. Should be maintained below 20ppm. All the fishes will be affected with time and exposure. This must be rectified.>
Very high algae growth also.
<Another bad side affect of high nitrate, overstocking....>
I guess I'm questioning if my problems are related to my water storage tank, transfer set-up, or softening process, or something else.
<As above, I fear the UGF is the culprit. Test your make-up water storage tank; always be sure to aerate and/or circulate your make-up water if you store it for any length of time (hours, even).>
Thanks,
John Rogers
<Wishing you well, -Sabrina>

Silver Dollars - Determining Their Sex
Hi Guys - I am getting back into the aquarium hobby after a 10 year hiatus. This time around, I am interested in the possibility of breeding.
<Hey, this isn't a dating service... Oh, you mean fishes... sorry>
 I have three small Silver Dollars (smaller than a quarter).
I have the round, all silver variety that has no spots on them. They all seem to have red on their anal fin. I went back to the store and the other eight in their tank also had red on their anal fin. I have read that this is how to determine if they are male or female.
<Mmm, nope. There are just some species of "dollars" that have red anal fins... in good health, care>
 Are all of these males or is there a different way to determine if I have a female in the group of three that I have?
<Really only with time, size/growth... and apparent "fullness" of the females... very likely you have both sexes...>
I know that I have to wait until they grow up to mate but I would like to possibly determine their sex now rather than having to by an adult female in the future. Thanks for any assistance. Mike
<Mmm, please see WWM, the Net... re Metynnis, Mylossoma... species. Bob Fenner>

Poor Pacu, Cramped Quarters - 08/23/2005
Hi. I saw your website and thought I'd try this question. I'm an intern at a Baltimore hospital which has a 28 inch Pacu in a small tank.
<Yeeee-IKES!>
Apparently no one knew it would grow this large when it was purchased several years ago and the Baltimore Aquarium won't take it and they can't put it in the bay.
<Certainly not.>
So no one knows what to do with it, and it's too big to even turn around in its tank. Do you have any suggestions for situations like this?
<Well, this will most certainly be posted on our dailies.... If you like, you can offer contact information for us to post with it, in case a reader wishes to contact you to offer a new housing arrangement for the animal.... Otherwise, you might try offering it on Aquabid.com or Ebay.com, or check with the local aquarium clubs in your area to see if they have any members that would be interested. As a last resort, you could check with local fish stores to see if any will take it. I hope it goes without saying that, once this animal is in a new, more appropriate home, do NOT consider another Pacu for this tank!>
Thanks, W. Gilmer, md
<Wishing you and your resident Pacu well, -Sabrina>

Silver Dollars with Fin Damage 8/21/05
I asked for help a while ago with my Silver Dollars looking extremely poorly. Ich causing large sores on their sides, and fin rot, you suggested a Furan based medicine and the continued use of Rid-Ich+. I'm now using Furazone-green (contains: Methylene Blue: 2.5mg, Nitrofurazone (Monofuracin): 122mg, and Furazolidone: 24.4 mg.) and I've doubled the dosage to one capsule twice a day as directed on the package as well as the Rid-Ich+. I've been treating one silver dollar in a ten gallon tank setup with no substrate under my 90 gallon for 10 days now. Figured this was a good location as this is a large, stressful fish and its inside a cabinet. I've noticed the major loss of ich, and the slowly shrinking sores, but the fins, though no longer discolored, have not seemed to have grown whatsoever. I was wondering what other practices I could take to speed this process, perhaps lowering the ph and adding softer water (distilled percentage)?
<After the sores are gone then the disease is practically cured. Now the fish needs to heal. Sometimes the fins get fungused too. These fungused fins to not regenerate. You will need to remove the fish from the water and clip the fins back to past the damaged area. they will then regrow but not as nice as if they were never damaged. Fins diseased back into the caudal peduncle usually do not regenerate.>
The ten gallon does have a large filter, in fact its an old, fully cultured penguin 330 Bio-wheel, I shut this down for about 45 minutes every time I add medicine. I'm only changing water when the fish seems to be breathing harder than normal, should I be changing it more often? Any specific help is greatly appreciated. Thanks again!!!
< Check the nitrates. The disease causing bacteria continue to thrive when nitrogenous wastes are present.-Chuck>

Silver Dollar Question 8/23/05
One more question please: after the sores are cleared, and their fins are clipped back, do I still have to quarantine them? Or can they go back in the 80 gal?
< Put them back into the quarantine tank until the fins start to grow back.-Chuck>

Silver Dollar Problems 8/21/05
Ok, this makes sense, the silver dollars never had good fins from the day I got them with my used tank purchase, from what I understand they are quite old fish, around 5 years old. But no matter, I'm not too much worried about the way the fins look, as long as the sores close up. How do you suggest restraining the fish out of water? Under a towel, and I imagine this should be done in intervals of just a few seconds. Thanks for replying!!!
< If you want to take them out to clip the fins then you take a large soft net and catch them. In a shallow dish you place a clean bath towel that has been soaked in the aquarium water. Catch the fish and place him on the towel and cover him up with only the section you want to work on exposed. Use fingernail clippers to trim the fins back past the damage. Silver dollars have very fine delicate scales that are easily damaged. If the areas get damaged then you might be back to square one.-Chuck>

Pop Eye on a Silver Dollar 8/3/05
Hi, I am Janet. I have a 55 gal fresh with 10 white clouds, 4 black tetra, 2 spotted Cory cats, 2 dwarf Gouramis, 1 blue magic dwarf Gourami (the other died in this heyday I have been having) , one goldfish, one black moor, 2 scissortail Rasbora and 2 six or seven year old Silver Dollars that were given to me by a friend when his wife died. They were her babies.
Hi Oh Silver came down with Popeye then a god awful case of dropsy. I put in Melafix for the seven day prescribed and Hi Oh didn't really improve much. I changed out 25% of the tank, put in Stress Coat and Stress Zyme and some Methylene Blue. Hi Oh looked bad yet. I went searching on the internet and found your site with salt treatments for these diseases. I didn't have Aquarium Salts but another site said Kosher Salt would do too. So I mixed up the salt (one gal to 4 teasp Kosher salt) popped Hi in and watched him for distress. After 3 min.s (of the 5, unless distressed) I thought he looked like he wanted out. So I put him in the tank. Next morning HE LOST ALL THE POPEYE AND MOST OF THE SWELLING!!
I did a test and found my nitrates were 160 so I did another water change out of nearly 50%. Put in Stress Coat and Stress Zyme and Meth blue. My test today shows PH 6.0, Ammonia 0ppm, Nitrite 0ppm and finally, Nitrate 0ppm. It seems Hi Oh is getting Popeye again and I think his pal, Long John Silver is too. Oh, I put in new carbon filters in case of something in the water affected the old new filters I had in.
Hi looks great other then that. A very small swelling on his cap (above his eyes/face), looks somewhat silver in most places, eating, swimming all about and with his buddy.
My question is should I start over and put the two in a hospital tank and treat with Melafix again or just do salt dips again? How many times can I salt dip a fish and at what frequency.... daily, every other day, ???? Salt seems to best work to bring down swelling. I have been fighting this for 3 weeks now and Hi is still here. He does sit stationary a bit crooked but he swims great. I think he can see yet out of his eyes. So far Long John is puffy in one eye.
This whole mess started with fish from PetSmart and putting their water in my tank. I didn't know not too since I read to do it in a dumb book, only to find out NEVER put water in another tank. I have NEVER tested water before so that is all new to me too but I desperately want to save the boys. Please help me : (
< The high nitrates are stressing your silver dollars. Keeping them down to under 25 ppm will be very beneficial. I have found that salt dose reduce the swelling and some fish do recover enough to be cured from this internal bacterial infection but just don't seem to be cured. I would recommend Metronidazole to treat the infected fish in a hospital tank so it won't affect the good bacteria needed to break down the fish waste.-Chuck>

Silver Dollars Getting Better 8/4/05
Thanks Chuck for the response you gave. I could not figure for the life of me what was causing the problem!! I do have the nitrates (never tested water till all of this happened..... last time I had a fish tank was 1977, didn't test water back then and didn't seem to have any trouble but we would bleed off the tank some every week and change water.) down to 0ppm (Yellow) and Hi Oh and Long John are Popeye free. Hi Oh is over his case of dropsy and is swimming around with Long John and eating food like a vacuum eats dirt.
The biggest improvement was always seen after a salt dip and all disappeared after I calmed my nitrates. I REALLY am GRATEFUL that I found your site and read what you said on salt dips and Silver Dollars. Hi doesn't look quite the same as he did but he is healthy and eating good again. He still is not quite as active as LJ and he is not fully silver anymore but he has had a monstrous 3 weeks and, believe it or not, Long John pesters him till he swims with him. It is the funniest thing I have ever seen a fish do.
Thanks again SO MUCH, Janet
< Glad things worked out. Thank you for your kind words.-Chuck>

Silver Dollars Looking Poorly 7/16/05
I have four full grown silver dollars that came with my 80 gallon tank when I bought it used. I let the previous dilrod owner bucket them with the three huge balsa. Well, when I took them out of the bucket, they were beat to hell and back. Ever since they've had body rot, fin rot, lateral line disease, and ich. I've been dumping medicine in there like crazy (Melafix, PimaFix, and RidIch) as well as keeping the tank as clean as possible. These fish are the only ones with the problem, nobody else in the tank has any disease at all. So I was wondering if this is what they call Neon Tetra disease. or something like that. If so, should I put them down? Or give them away to someone who could rehabilitate them. keeping a fish from getting ill is one thing, but rehabilitating them is another, especially when they are seriously ill. Polara_Blues
< Fine scaled characins like silver dollars really get beat up every time they are moved. Use the Rid-Ich to get rid of the ich as per the directions on the bottle. This is a very good product but needs a little time to work. Once the ich is gone use a water conditioner that has an additive specifically for wound control. There are many out there. I like Bio-Coat by Marineland. I don't like using the MelaFix and PimaFix to treat diseases because they really seem ineffective and you will need to use antibiotics anyway. If there are signs of bacterial infection like fin rot and open sore on the body then you need to treat. I would recommend using a Furanace type product-Chuck>

Sick Silver Dollars II 7/17/05
Ok, sounds like I was going to wrong way with the medicine. Although I have noticed a considerable drop in fin rot with the MelaFix, it hasn't gone away.
< At best this stuff is a bacterial inhibitor.>
I'll take your advice seriously. Thanks!
<Good Luck.-Chuck>

Moving... a large, crowded Pacu 7/14/05
Hi,
<Hello>
We will be moving soon, and we are wondering how the heck we are going to do so. Since our Pacu is now about 2 feet long and 1 foot tall. He is currently in a 60 gallon tank which we upgraded for him 2 years ago.
<... too small>
He use to be in a vertical 45 gallon. Anyhow, the last time we moved, he suffered a fractured tail; he jumped out of the bag, landed his tail on the edge of the bucket, and flopped on the floor. It was a nightmare!!
<Think about the fish>
Since then he has grown a few inches, and we don't want the same thing to happen again, do you have any suggestions?
<Yes... this fish is best removed from the tank with the use of large, thick plastic bags (pet fish or trash can variety), perhaps doubled, tripled for strength... slowly, deliberately scooping up enough water, the fish... and enough strong arms present to lift all out of the tank... then using oxygen gas to fill the bag/s, seal... and expediently move>
Also, how to you travel 400 miles with a fish that big, without killing him?
Shoselyn Novo
<The oxygen will help... but perhaps it's best to leave the fish with someone, a shop that can/will ship it to you (air) after you're situated. I must state that this is not an adequate space for this animal, species... Unless you're able, willing to provide something of a few hundred gallons, I would find it another, better home. Bob Fenner>

Pump selection... misplaced priorities 7/12/05
Hello, I was shopping around for water pumps in mail order catalogs. I'm looking for something with raw, unrestrained power
<Good terms>
that can create a current big enough for my 20 inch Pacu to swim against in a 90 gallon tank,
<... yikes, you need a much larger system for this fish... MUCH>
but it needs to about my budget, oh say around $65. I did find a via aqua pump, fully submersible, 1,321 gallons per hour at $59.99 from Drs. Foster and Smith. Do you guys know of anything with more power for about the same price? Doesn't necessarily have to be fully submersible, and I'm not worried about sound or power usage, it wont be a 24 hour thing. Thanks a bunch! You guys are great!
<... I would not be so concerned with the purchase price here as much as the operational cost... electrical consumption will be more than the pump cost within a year. Look to the Eheim line IMO... more to invest in up front, but quiet, long-lasting, energy conserving units. Bob Fenner>

Re: Colossoma, human nature 7/13/05
I think you'll find this story quite familiar as I've been getting advice from you guys for a while now, but the fish is in a much better condition than he was before. I originally bought him in an 80 gallon with filtration adequate for maybe a 50, and he had 2 huge balsa, 4 full size silver dollars, a giant Pleco, a jack Dempsey, couple Corys, and a Gourami with him. now the 80s been fully upgraded and the Pacu has been moved to a much nicer 90 gallon all by himself. The 90 gallon has about 750 gph of filtration at this time. Keeps him sparkling clean with gravel washing once, sometimes twice a week when he decides to eat more. The previous owner actually had no idea of what to do with him, and his wife was tired of cleaning the tank DAILY! Can you believe that? Scrubbing an 80 gallon tank every day!
<Too much life, too little space, filtration. RMF>
But right now I'm out of a job and low on money. But my parents (I'm 17) plan on building a rather large green house in a couple years. Well, they decided to make it even larger to accommodate a 300 gallon heated pond design that I plan to custom build above ground for Pacu. He should be happy in that system to the end of his days I think with plenty of other small fish to swim with and lots of plants to eat.
<If it lives in the meanwhile>
Right now I can tell he'd like some moving water as some times he goes to one side of the tank, puts his nose against the glass and swims as fast as possible against it sending sand and his one plant everywhere. Good for keeping detritus out of the gravel, but when he's done the tank doesn't look so beautiful anymore. So I thought maybe a good strong current for part of the day might get him some exercise. What do you think? Open to any ideas. I will check out the Eheim pumps, that sounds good. Thanks again!
Here's a link to a picture of Pacu's tank for you to see how clean and healthy he is! If only I could get a job doin this kinda thing!
http://www.deviantart.com/view/17741252/
The Pacu and the Gourami you see here have since been removed to the 80 next to it, and the Jack, due to poor accommodations for an aggressive fish, was given away to an enthusiast with a 150 gallon tank. last I heard the jack hit a BIG growth spurt and is developing a small frontosa style lump on his head.
Polara_Blues

Ongoing Pacu in a tiny tank, pump... 7/14/05
Thanks, I've been doing everything I can to keep him healthy, he is currently disease free as far as I can tell, and his tank is always clean enough that he almost never has to open his mouth to breath hard. I'd get a new tank for him in the mean time, but 150 gallon cube style tanks run up over $1,500 in my area, that's without a lid and filtration. Fat chance on finding a used one too. Even though Pacu is the most important thing here, I have to stop my self from taking out a loan.
Polara_Blues

Re: Hmmmm...I might think about that.
Polara_Blues
<Ah, good. BobF>

Silver Dollars with Popeye
Dear WWM Crew (and Mr. Fenner if you're out there)
First, Thanks for the help on my first problem which resulted in the deaths of my 10+ year companion silver dollar fish Now I have taken your previous advice and have been aging water and refilling the 55 Gal tank from that. My newest arrivals (5 silver dollars) have been constantly plagued with on problem after another. First - my water here is hard!!, but my previous silver dollar fish lived long - until my water softener changed salt mixes on me which I believe resulted in the "snow storm" that killed off all my fish but the angels.
Here's the history:
55 gal tank with hard but clean and regularly changed aged water.
5 Silver dollars, 2 clown Plecos and 3 neon tetras added to tank with 4 gold angels - that had survived the previous 'snow storm'.
The silver dollars and neon tetras got ich shortly after being added to the new tank. Treated with elevated Temp. and salt. No more ich, but Silver dollars had a white sheen and two of the five silver dollars began bumping along the bottom of the tank and running into things like they were blind. I treated the tank with Pimafix - all the silver dollars recovered. Within a couple of days the silver dollars eyes began to cloud and bulge (pop eye). This has afflicted most or all of the 5 silver dollars. The other fish seem to be unbothered by this affliction, but one neon died and the others were stressed when I added both PimaFix and MelaFix ( I thought I read they could be used together).
Pimafix seems to work the best - clearing the eye cloud issue, but the eye bulge continues (several of the silver dollars show the skin area around the eye where it is stretched). This problem seems to go on and on.
I read on line that Medi-gold was good for this, but I couldn't find it in my area, so I settled on the next recommended thing (Maracyn-two). While it would be nice to get medicated food, I should state that the Silvers continue to be very active - eating everything in sight - including the pieces of Maracyn-Two tablets that flake off as the tablets dissolve!
Do I really need to soak their food in this medication if they are willing to eat it straight?
Anyway, I've had these guys since February and they've grown from the size of a US quarter to larger than the top of a soda can. I would hate to lose them now because I'm kind'a getting attached to them. Any suggestions would be appreciated (again). Thanks for all your help. MY previous email (and your response) follows.
< South American fish come from soft acidic waters. Many have a difficult time adjusting to the aquarium and to the change in water chemistry. If they don't die outright from the hard water they usually are stressed and are vulnerable to catch all kind of diseases. The later sound like the current problem you are having. Pop-eye is a disease where bacteria build up behind the eye socket. as the bacteria grow and multiply they put pressure on the back of the eye and push it out. I would recommend a 30% water change, vacuum the gravel and clean the filter. Then I would treat the tank with Metronidazole. It is effective on anaerobic bacteria.-Chuck>

Silver Dollar Compatibility
Good day ladies and Gents,
I have two Silver Dollars (Metynnis hypsauchen) that have outgrown my tank. They've been together in my tank for two years now. A friend of mine has a 75 Gallon with a mated pair of the same fish, and he said he would gladly take them. I looked through the FAQ's and did not see an answer to my question so I feel safe in asking it.. :) I was just wondering if they're would any aggression between the pairs, and if the tank is large enough? Thank you as usual!
Heather
<In all likelihood these four will not only get along, but be much happier in a larger grouping... this is how they live in the wild. Bob Fenner>

Pacu teeth and food/wafer evaluation
I just thought you guys would be interested in a little product assessment considering algae wafers and Pacus. My Pacu is nuts over Algae wafers, so I've been shopping around for the ones that would be best for him. The two I've been using are pretty much the same as far as ingredients go. These products are Top Fin and Hikari, I've found that Hikari are actually better in two ways: they are about a dollar cheaper and have a half an ounce more in weight, also the wafers are a lot tougher and Pacu likes them that way because they feel good on his teeth. He actually takes the time to chew them and you hear a crunch that you can hear from the opposite side of the room. So there ya go, they are better for Pacu owners. Since I started feeding this to Pacu his teeth have grown in more plentiful and there are any tell tale signs for sore teeth anymore. Of course he gets a very plentiful diet of what ever just happened to be in my salad that night too. (No dressing of course) He seems to like grapes a lot too.
<Thank you for this input. Will post/share... you've made many Pacus happy with your testing, reporting. Bob Fenner>

More Silver Dollars!
My silver dollars spawned again! I didn't have them in a tank setup for this, I just happened to be in the right spot at the right time to protect the eggs from swordtails with a net and managed to siphon out about ten of them. I don't have another empty tank so I'm attempting to hatch them in a hanging net within the tank the parents are in, and I figure that since the water parameters were good enough for them to spawn, I will touch nothing.
<Good idea>
The eggs are still currently clear a couple of hours later with a spot in them. My question is: what color will they turn, and how long should it take them to hatch?
<Should remain clear except for the growing juvenile, their eyes... about four days to hatching in the low 80's F... you should be culturing food for them NOW... read about this on the Net... "Rotifer Culture">
-the Pacu kid.
(am I just good at keeping the water nice? Or did I just get lucky? I never really do tests on water parameters, I just watch the fish and go with the feel.
<Given passable circumstances almost all life will reproduce itself... a high priority eh? Bob Fenner>

Pacu
Hey WetWebMedia guys, I got Pacu in his new 90 gallon! Boy was that an experience, it was weird, he didn't move a muscle until he was in the water in the new tank and then all hell broke loose, he even got caught in the net!
<Yikes... I've been present at the move of many a Colossoma... better NOT to net them, but instead direct into large, thick plastic bags, drain off most of the water, and pick them out one at a time this way>
Fortunately no blood was lost, just some really split fins which I'm using wide spectrum antibiotics to help. So now, I just have a pouting Pacu that wont eat much, I'm sure he'll eat more in a couple days.
<Agreed>
So here's my question, all of the fish that I moved into the new tank (Pacu, Pleco, Jack Dempsey, weather loach, and Pacu's pet Charlie (The Gourami that likes to school with Pacu @_@)) all don't like to have the light on, they don't do anything at all. But if I have the light off with other lights on in the room its like a party in there. All I have is a 48 inch single tube fluorescent light fixture and I'm wondering what the best light would be for night time viewing.
<Mmm, what ever suits you, the human/s... best to put whatever lighting you use on a timer though... to keep the cycle consistent>
I'm not looking for anything expensive, just like maybe a hardware store black light for instance. Any suggestions? Thanks.
<Bob Fenner>

Re: Pacu lighting
ok, as long as the black light doesn't mess up their colors or anything, but perhaps I won't use one and just find something a little softer. Not sure yet. What was really hard about the move though, is he's 19 inches long and 20lbs easy,
<Yes... have seen C. macropomum in captivity near thirty inches in length>
I didn't think that a plastic bag would be right, could rip even.
<You are wise here... I'd double or triple bag... with 4 mil bags... and have two or more friends to help lift out of the tank>
Unless you guys have something special that you would use? Perhaps a tarp sling between two plastic pipes that is closed on the ends? That way you could coax him under it and lift it up around his sides and close the pipes together. I'd like to know for future use. Thanks!
<Not anything that might scrape these fishes... they have very fine scales and soft fins that are easily damaged... as you know. Some public aquariums use anesthetics in moving these serrasalmines and other large, strong specimens. Bob Fenner>

Re: Pacu moving
Ok, I don't know where I would get any anesthetics and that could be dangerous (cardiac arrest or what ever) so next time I'll try the 4 mil bags, but maybe more like six. Lots of thanks!!!! Pacus are great pets, a little jumpy, but mine is friendly enough to eat out of my hands and let me scratch his sides with the cleaning tubes from time to time, he's a real great pet! Sometimes I get a little nervous that he may erupt the tanks, so when I'm not home I actually cover the front of the tank with a blanket Thanks again!!!!
<Thank you for this. They can indeed be gentle giants of wit and grace. Bob Fenner>

Hey guys, my Silver Dollars are mating.
I don't know if you remember, but a couple of months ago I had questions about diseases that were in an 80 gallon tank that included a very large Red Belly Pacu (pic. included) four silver dollars, a couple Balas, a Jack Dempsey, a Large Gourami, some Corys and a very large Pleco. Now I know this is bad to have all these fish in this tank and it's really crowded. But somebody had to adopt these fish from the family that wasn't taking care of them. They were riddled with Ick, fin rot, and hole in the head disease and they also didn't have adequate filtration ( a pitiful old Penguin 300 that looked like it hadn't been cleaned or changed in months) But I've added a Magnum 350 pro kit with a Turbo Twist UV Sterilizer which is taking care of all the Ick and fin rot beautifully. Also, a couple days ago I picked up a used 90 gallon tank with every thing I need except the adequate filtration for $150, although this time there's no fish in it When all this first started, the Silver Dollars were in the worst shape, I thought they would surely die. But I've nursed them back to the point where their mating! Believe it or not, these people just happened to have one male and three female in there, and they decided to mate right in front of my Grandparents during thanksgiving dinner. That was really embarrassing let me tell ya.
 So my question is: how can a set up a breeder tank for these larger fish (6 inches long) so that when they are ready to lay the eggs the eggs are protected. Also, how does this work with Silver Dollars? I've successfully bred over forty sword tails in three batches now, but I've never bred an egg laying species. Please help!
< Silver dollars are egg scatters as are most characins. The male and female do a little dance and will swim side by side. As they do this the female releases the eggs while the male fertilizes them. The eggs drop all over the bottom of the tank and ornaments. They are quickly eaten if they are not removed. The key is to set up a tank that is big enough for them to spawn by you need to keep them separated from the eggs. Go to the hardware store and get some lighting panels that resemble egg crates. Cut them to fit your tank and suspend them off the bottom. Next time the fish spawn the eggs should drop below the egg crate where the fish cannot get them. ^Then remove the adults. Another method would be to cover the bottom of the tank with glass marbles. The eggs would fall between the pore spaces between the marbles. They prefer to spawn over tuffs of plants some java moss or an artificial spawning mop would help. The eggs are very susceptible to fungus so the tank must be kept clean. Water temperature hardness and pH are all critical to get a successful hatch. Water should be clean, warm , soft and acidic for the best results. When the fry become free swimming they can be fed. depending on what species you have the adults may not eat the fry. They should be fed infusorians until they get big enough to eat baby brine shrimp and crushed flake food. Females will be plumper than the males. Some species do not eat the fry at all! Breeding these fish is not that common . Good luck.-Chuck>

Freshwater Tank and Pacu
Hey Guys, I found your site a few days ago and I can't stop reading it!!!
Thanks for all your support!!! It is informative as well as confusing, and I mean that in a good way as in making you think and raise questions. So I hope you don't mind answering a few of mine.
A little background as to where my questions lead. About 2 years ago I set-up a fresh water 55 gallon tank in a dialysis facility where I work for the patients, which they enjoy. The fish that were donated at the time included a Pacu. I knew eventually I would have to transplant her into a larger tank. Since then the other fish have been removed and placed into other tanks.
Recently, the facility was donated a 265 gallon tank, stand and some accessories which I am now preparing to put our larger Pacu in alone. The tank came with 2 magnum 350's but in research I discovered that the combined flow rate of these pumps would not turn the water over the enough per hour, plus the pumps are only are mechanical and chemical filtration. So I am building a wet/dry from scratch with a little giant TE-5. I estimate should turn the water over about 1200 gph, to augment the magnum 350's. Is this over kill? Can you have to much turn over per hour?
<No.>
Will this also be too much turbulent return flow for a Pacu?
< Pacus come from the Amazon and can handle a pretty good water flow.>
She is about 10 inches in length now.
If it is, can I just incorporate the mechanical and chemical filtration into the wet/dry and ditch the magnums?
< You can just use the wet/dry but I always use a second system as a backup.>
Ok, next bunch question is in regards to nitrate and bio-balls. I am having difficulty determine the amount of square footage of bio-balls that I would need. Do you have a formula in relation to tank size or a recommendation? I am also reading that bio-balls are being removed once nitrate levels begin to rise when approaching the recommended maximum levels. Do you remove them a little at a time until you reach appropriate or equilibrated conditions that coincide with regular water changes?? Am I totally on the wrong track and confusing this with marine aquariums?!?!
< Too many variables. How many fish? How big are the fish? How often are you going to do water changes? The problem with building these big massive filters is that while they remove the waste from the tank, the fish waste is actually still in the system and needs to be removed. If you only clean it once a month because the water flow is not restricted then you still have a lot of fish waste that is generating lots of nitrates. You still need to service the filter regularly to get the nitrates down or the water changes will drive you crazy. Reducing the bio-balls does nothing to reduce the nitrate content unless they are so loaded with junk themselves that they become the source of the nitrates.>
Ok last bunch I promise. How to acclimate, my Pacu to the new tank. Being I work in dialysis and water treatment, I have access to RO water polished by DI, post UV and Ultrafilters with a carbon, multimedia, and softener pretreatment. So since the water I will be using will be for the most part is inert, I was planning on cycling the water between the two tanks with a pump at a rate of about 2-3 gallons per day for about two weeks. Then gradually increase the rate to about 100 gallons an hour over the next week till the tanks equilibrate themselves in pH, hardness, nitrates, temp. Yes, No, Maybe??? Any other conditions to avoid stress and shock to our mascot I should be concerned with?
< If the Pacu is currently in tap water then set up the new tank with the same matching tap water. You have had him for two years so then you can match up the water to what he is in now. Using "pure" water without a buffer can lead to dangerous consequences.-Chuck>
Thanks guys, I have never set-up anything this size before or transplanted a living being of this size. Failure is not an option!!! This will help me in a couple of years to transplant our Pacu again into a larger tank which I know she will eventually need. All your comments, concerns and criticisms will be greatly appreciated.
Humbly,
John Mahalko

Bend Over so I can Take your Temperature
What temperature does an outdoor water pond need to be for a Pacus freshwater piranha?? They have wintered in a indoor tank and were in the pond the past summer.
< These fish are from the Amazon River and I would recommend that the lowest nighttime water temperature be no lower that 75 degrees F. Any lower than that and they could come down with ich and be difficult and expensive to treat. -Chuck>
Kathy

Red Bellied Pacu 3/16/04
<Hi, Pufferpunk here tonight>
I have two red bellied Pacu. They are about a year old or so, and are roughly 8 to 10 inches, a pretty good size. Up until today, haven't had a bit of problem with them. I turned the light on, and noticed that one of the Pacu, for lack of a better description, almost albino like or turning kind of milky white. They've both been growing nice, very active and eating well. It's only the one fish. Any suggestions ? The PH is between the 6.5 to 7.0 area, temp is kept as close to 81 degrees as possible.
<PH sounds kind of low. Have you tested for ammonia? How big is your tank? Those fish are high waste producers, creating a huge bioload. I suggest 50% weekly water changes & serious filtration! I actually do that on all my tanks. Are you aware that Pacus supposedly can grow up to over 3 feet in length? The fish is very round and thick. Wild specimens have been weighed in at around 70 lbs! A quarter sized baby will quickly grow to over 6 inches within a year. Because of the eventual size of this fish I recommend at least a 300 gallon for just one! Do not buy this fish if you don't plan on following through. They are a huge investment, but it's worth every penny. Most of these poor fish is doomed to die at an early age or is cast aside and abandoned in a pet store.>
Any help would be greatly appreciated.
Thank you for your time
sincerely Dave
<Good luck with your giant fish. ~PP>

My Piranhas (Sung to the tune of "My Sharona!")
<Hi Katie, I'm not the one that answered your previous email, but I'll assist you with your piranha problems.>
I do treat them with an antibiotic but it seems like every time we do that there fine and then it comes back even worse and then it starts with two and then all of them...
<Then this is a sign that the tank itself needs work, not just the fish.>
my boyfriend checked the ammonia level the other day and it was fine we can't seem to maintain pH..
<I don't know the size of the tank you have the piranhas in but these are rather messy fish and need lots of tank space. Piranha have evolved from fin-nipping species of fish. Their ancestors were small little fish that actually survived by eating the fins of larger fish. And through evolution they evolved into the larger voracious Piranha breeds you see today. That means that these fish will nip at each other if not given enough room. And when fish are left in an environment when their tankmates nip at them their health quickly deteriorates leaving them vulnerable to many different types of parasites and sickness. Aside from needing a large space, the major concern with any piranha owner is that these fish need some of the best filtration that can be offered to them. I had raised friends piranha for a while, when they were away at college and during that time I realized that only the best filtration should be given these fish. I doubled the filtration of the tank to help with seemingly endless illnesses... I found that the increased water flow and cleaner water made a great deal of difference. As for that, I would also suggest you set up a quarantine tank if you don't already have one. When I fish becomes sick remove it from the display tank and move it to a separate tank. This removes the chances of the problems spreading to the other tankmates. Also a sick piranha is more likely to be picked at by others, which isn't fair to the sick fish.>
also what does that mean when they float near the top or they float kinda sideways not completely only a little bit and it doesn't happen all the time.
<When fish that don't normally float near the top are seen there, that typically is a sign that their isn't enough oxygen in the water for the fish. Oxygen levels are higher at the surface of the water where oxygen exchange happens. This is a sign that you are not offering the right environment for these fish. You will need to bump up the filtration on these fish, and offer powerheads, and airstones/pumps to help with surface agitation to help increase the oxygen exchange. I feel that the reason these fish are getting sick is that the water quality is not up to the standards it needs to be. I suggest you check out some of the piranha forums online and talk to the owners. You will no doubt learn a great deal of info from them. A few places to start out with is www.aquatiqterrors.com or www.piranhafury.com. Both of these forums offer knowledgeable crew members specializing in piranhas.>
thanks again
Katie:)
<Good luck with the fish, and hope they do get better. -Magnus>

Piranhas
Hi my name is Katie...I have a couple of questions thank you by the way your website has already answered some of my questions! I have a 55 gal tank, if I got them a 100gal to 150 gal tank will they get bigger, I have a one female
and she's big but all my males aren't very big at all I have 5 all together)
>>A bigger tank is always better. You will have a hard time with water quality in a 55g. Do you know your ammonia, nitrite, and nitrate levels?<<
My 2nd question is one will get eye cloud and then the rest will get it all they are eating right now is freshwater shrimp could that be a problem?
>>Yes. You need to treat them with a broad-spectrum antibiotic. Again, what do your nitrates measure?<<
I only have one filtration system in there could that also the problem should I add some more I've had them for almost a year now so that would make them almost 2yrs old and it's been the same filtration system...
>>How often do you do partial water changes and clean the filter?<<
They also get really pale during the day and night for about an hour there bellies are really red and then they get really dull. I just want to make sure I'm doing everything o.k. love them and wouldn't want anything to happen to them. well I appreciate it if you could reply to this when you guys have sometime. thanks Katie:)
>>You are welcome. -Gwen<<

Silver Dollars
I recently converted a 60 gallon tank from salt to fresh. It is currently in the process of cycling.
<Sounds good!>
My ultimate goal is to have a school of silver dollars, accompanied by a couple schools of smaller fish such as neon tetras.
<Ultimately, the silver dollars will grow large enough to happily gobble up Neons.... Though they are primarily vegetarians by nature, lunches-with-fins are still lunches-with-fins.>
My question is this, assuming I have 8 small 1" fish in this tank, what is the largest school of silver dollars that my tank could support.
<Well, considering that silver dollars top out around 5-6 inches (depending upon what species you get), I would consider than any of those 1" fish would be at risk of being eaten. But, assuming that they don't, and everyone lives peacefully, and you're not talking about 1" waste factories (baby goldfish, baby Oscars, etc.), I would think three or four adult silver dollars would be comfy in a 60 gallon tank. While small, you could try more, but you'd have to watch for aggression and thin them down as they grow - and they do grow pretty swiftly.>
Thank you for your help. Dane
Sure thing. Wishing you well, -Sabrina>

Pacu
I have a red belly Pacu that is lodging in a 55 gallon tank.
<Just so you know, the Pacu will out grow that 55 gallon tank. They get very big.>
I transferred him from a 30 gallon tank a week ago--my question is--why does he seem afraid of the florescent light compared to the light that was provided by the typical pet store hood for the 30 gallon tank?
<Pacus really don't like bright lights, but the real problem is that it's just getting used to it's new home. Try not to keep the lights for a few days... allow it some time to get used to it's new tank. Then once it's seem to get accustomed and less flighty then you can turn the lights on more. Just give it some time and it should be back to normal.>
he stays at the corner of the tank until the light is turned off--then he swims around--once I put the light back on he swims erratically hitting the sides of the tank and acts afraid the whole time the light is on--should I put a light filter on to change the color of the bulb??
<If you want to change to a lower watt bulb that might help it. But, I really think that the problem is that the fish is just adjusting to it's new environment... give it some time and it should be fine. -Magnus>

Bob... pics of wacky fishes
Hey, Bob... I came across some neat fish today (brindle cod... handsome enough to not want to eat). Hmmm... can send pic if you care to see. Attached though... a Thai pig nose FW puffer (neat to me)... and (no joke) a piranha that should have been culled: two fully functioning mouths. Sigh...
<Bizarre. I could eat twice as much! I sense a Hollyweird potboiler coming on! Bob F>

What's in a name....
I am interested in Parrot Pacus, the trouble is that there is not a lot of info on the web, could you give me some? For example, what is the minimum tank size for two or three of them, how easy are they to care for, and where can I find them?
--Aaron
<Hi, Aaron! First off, by 'parrot' Pacu, do you mean Ossubtus xinguense? Fishbase.org says they max out at about seven inches, so *if* you can find them, you could probably keep a few comfortably in a 40 or 55 gallon aquarium, though as always, larger is better. As for ease of care - well, like you, I'm having a great deal of difficulty finding information on this fish. I'll refer you to WWM's piranha/Pacu/silver dollar information: http://www.wetwebmedia.com/FWSubWebIndex/serrasalminae1.htm . And now, for finding them. This is going to be the tough part. Do a Google search on the scientific name, and also get in touch with some of the companies that deal with south American fishes (I can only think of www.belowwater.com off the top of my head, but I know there are plenty of others). I believe you'll have some real difficulty trying to find this Rio Xingu native. I think if you do find them, they'll come with a hefty price tag. But looking at the FishBase pic, that is indeed a cute fish. -Sabrina>

MEANWHILE MEET THE PIRANHA THAT MURDERS FRUIT
11:00 - 01 September 2003
Piranhas have a reputation as deadly and ruthless predators, capable of stripping a carcass to the bone within minutes. But yesterday scientists revealed how a newly-discovered relative of the sinister species has developed a distinctly sweet tooth, enjoying chomping on fruit.
The fish is one of a range of bizarre and colourful marine creatures revealed to the world for the first time this weekend. A team working in the rainforests of Venezuela have identified 10 previously unknown species of fish, along with a new breed of shrimp.
One of the new additions, an armoured catfish complete with a crown of protective spikes, was immediately dubbed "punk".
The team, US-based Conservation International, has also identified a new relative of the Bloodfin Tetra family, a vivid red and green fish named Aphyocharax yekwanae in honour of the native Indians who live in the area where they were found.
The discoveries were made in the Caura River Basin, around 300 miles south east of Caracas, an area of untouched tropical jungle crisscrossed by waterways.
Conservation International is now calling on the Venezuelan Government to make the 11,115-acre area a wildlife reserve.
Zoologist Antonio Machado said: "For its size, it's incredible what the area has. It's a hot spot that should be protected."
Conservationists fear the tranquility of the river basin will be shattered by human settlement, increased farming and fishing. They also claim it is at risk from a planned hydroelectricity project.
<Again, thanks to you Mike. Bob F>

Pacu Snout Sore
Hi guys,
<Hi, Andrew, Sabrina with you today>
How's it going?
<Not bad at all, thanks!>
I have a six foot tank housing 2 juvenile Pacus and one small black shark. The larger of the 2 Pacus has some injury around it's snout area, it looks similar to hole in the head but I don't know exactly what is wrong with the fish. He is feeding well and actively swimming around the tank, plus he is exhibiting remarkable growth. I am concerned about his snout though. I bought him at the shop having inspected the injury, which seemed minor at the time.
<Minor or not, it's always best to try to get only healthy, uninjured fish, as I'm sure you now know>
Do you know what is affecting his snout ?
<Well, with the pics you sent, it does indeed look like hole-in-the-head/HLLE. This illness typically affects large predators (usually cichlids) and can be brought about or exacerbated by constant poor environmental conditions or sometimes improper feeding. It can be a protozoan infection (Hexamita) and may also be worsened by systemic bacterial infection on top of that.>
How should I go about treating him ?
<Well, first off, absolutely keep his conditions pristine, for starters. Good water quality is a must. Moreover, I'd recommend to put him in a hospital tank for treatment with Metronidazole, which does seem to have some effect on this illness. His face does look pretty bad; he may never heal completely, even if you can kick the problem. Hopefully, though, you can at least get it to stop progressing, which will surely kill him eventually.
I suspect maintaining a healthy environment and letting time go by will be your best advice, yet I would appreciate your opinion as the snout looks quite serious - the flesh is exposed to the extent that the top dentition is clearly visible. I enclose some pictures to assist your speculation.
<Definitely good advice to keep his environment healthy ;) but in his case, I do recommend treating in a hospital tank. It does look quite serious at this point.>
Thanks for your time in advance, Andrew Hough
<Any time!>

Piranha's
I have noticed that your piranha spec sheet is off a little. You can look at other websites to get a better understanding.
It says that p. piraya is a max of 13 inches. That is a common Redbelly that can reach that size. P piraya can reach 20 plus inches. I am not trying to boast or anything like that. I just thought that I could help a little with your info.
Also the piranha that is listed as p piraya is a red belly. If you want I can give you a correct pic to use on your site.
It is one of mine, and no copyright infringement to worry about. I have learned a lot from this site and would like to give a little back. Thanks
Alex
<Thank you for the input and kind offer. Do send the Natterer's pic and I'll post it with credit to you. Bob Fenner
on FishBase: http://www.fishbase.org/Summary/SpeciesSummary.cfm?ID=8696&genusname=Pygocentrus&speciesname=piraya>

Silver dollar problems
Hi there, I have a question. I have a 150 gallon tank with 5 silver dollars in it (among others). One of the silver dollars is very large (6"-7") and very old (7 yrs?), another is just as large and around 5 yrs old, and the others are around 3" and 1 yr old. Not too long ago I noticed a bump on the side of the oldest one. It doesn't seem like a swelling or bloating, but more like a small protrusion outward (about the size of a pencil eraser).
It is on the lower rear portion of the fish, possibly near the digestive tract. It grew and grew until it punctured through the side of the silver dollar leaving a decent sized hole, with hard light brown matter coming out every once and a while (not like fecal matter). It eventually cleared up with no treatment and he looked fine.<probably an infection of some sort... maybe due to poor water quality/nutrition??
Now, the same thing is happening, only to the 5 yr old silver dollar.<would check water
quality ASAP. What do you feed your fish?> I don't want this to keep happening because it sure doesn't look too healthy.
Could this be some sort of bacterial infection of the digestive system, or something else like constipation.<Could be an infection of some sort normally they are caused by diminishing water conditions/ or nutrition deficiency>
And how do I treat this if I should.<A picture would help greatly since different people observe things differently>I have been feeding them the same food since day one (Tetra Min tropical)<This food is OK>,
and have never had this problem. Thanks for your help and knowledge.<Please try to send a pic...would help greatly
and make sure to give me the readings of pH, nitrate, nitrite and ammonia in your aquarium...IanB>
-Ryan-

Silver Dollars with torn fins
>Hi Bob/crew
>>Greetings, Marina for you today.
>I currently have 6 Silver Dollars, a Plec, a Bristlenose, a Synodontis Eupterus and 2 Pimelodella Pictus in my 125 gal tropical tank.  All the fish get on fine, are eating well and water parameters are correct. However, over the last few months the Silver Dollars have all developed torn fins to varying extents. All the fins are affected on the fish.
>>These fish can tend to abrade the heck out of themselves and each other, though the size tank you have them in should be sufficient to avoid this.
>The fins actually have pieces missing so I believe the Silver Dollars themselves are doing the damage (it doesn't look like Fin Rot). I have never seen any aggression however.
>>It doesn't have to be via aggression, just skittishness.  Have you any rough rockwork in the tank?  Also, set up an infrared light and spy on them at night, you could find a culprit making trouble at night.
>My main concern is to repair/heal the damage ASAP but am unsure how to do this other than to continue to feed a quality diet and ensure high water quality. I am also currently using a product containing Tea Tree Oil. None of these measures seems to be having any effect though.
>>I would stop using the Tea tree oil, myself.  Until/unless it's proven to do ANYTHING for the fish it's a waste of good money, in my book.  High quality feed will keep them from succumbing to any stress, and my guess is you're spot on about them doing this to themselves.  I find them to often be like high-strung horses, and often wont to bang themselves about.  If you're using any rough rocks, try removing them.  If you feed no live food, offer them some daphnia and mosquito larvae if you can (just about all other freshwater live foods EXCEPT brine shrimp would be good).  Other than that, I would ensure that a full 2/3 of the tank is planted thickly.
>Any advice on this would be much appreciated (the Silver Dollars are currently 3.5" approx and growing fast).   Thank you.  Ian Allen
>>You're welcome, I do hope this helps.  Good luck!  (Yes, they'll grow quite quickly in such generous housing!)  Marina

Re: Silver Dollars
I really want to put aquatic plants in my 55gal but I have 2 Silver Dollars that ate the previous plants i have tried. Do you have any suggestions on a particular species that may not taste good to them?.
<Some of the tough Anubias species might do here... and the less palatable Java Moss, Hornwort/Coontail (Ceratophyllum) might be worth trying... otherwise, you might consider building a divider blocking access to the plants (keeping the Silver Dollars separated). Bob Fenner>

Cloudy Eyed Silver Dollar
I have a Silver Dollar and her eyes became white, what does it mean? What can I do? Is there something I can buy?
<It could mean any number of things. Are the eyes pure white now, mostly cloudy, or just a little cloudy? Causes could be water conditions, external or internal injury, or disease. If it’s from poor water conditions then water changes should help. If it’s an injury then Melafix may help, if it’s from a disease there are commercial medications that your LFS will carry that should help. Please see http://www.wetwebmedia.com/FWSubWebIndex/fwsubwebindex.htm and the FAQ’s related to diseases, injuries, and Silver Dollars for more info.>

Piranha problem?
Hey what's Up! I would appreciate it if you could write back to me as soon as possible just bought 8 piranha for my tank. They are all babies a little bit bigger than a quarter. Anyway I went away for two days and my heater went crazy, I came back and the water was at 90 degrees. I bought a new heater now. I did a water changed added new water and added plenty of stress coat. My fish look like they are back to normal! Two of my fish fines are really damaged they Dorsal fin, it looks like they have been stripped down or eaten.
<Very likely have been chewed by the other Piranha... very common. Not the heater; many species (there are dozens) do live in water in the mid to upper 80's seasonally.>
Could their fins be prepared?
<Yes. They can/do regrow in time. Just need to keep the whole lot fed (a few times daily), provide enough hiding spaces (plants, driftwood...) and keep up your water quality>
Their eyes look cloudy. If these two piranhas died could I add two new piranha similar size to my tank.
<If the system is large enough. You need a good two hundred gallons plus for this many of the smaller size species of Piranha. Please see here: http://www.wetwebmedia.com/FWSubWebIndex/serrasalminae1.htm>
I have had my piranha for two weeks. I know once the tank is established you cant added a new piranha but since they are young could I added them???? Thanks A lot Barry

Silver dollars don't look normal
Ph 7.6
Ammonia 0 ppm
Nitrate 10 ppm or less
Temp 77
72 gal bow front
aqua clear 300 and two bio wheels
The spots on the dorsal fin do not seem normal. There are also larger spots on the skin. These silver dollars approx 4 or 5 inches long. They also appear to be mating. (swimming side by side and fanning their tails rapidly) The attached photo is the same fish full frame if you want to enlarge for a better view.
<The parameters you mention may well point to the mis-coloring of the specimens... these fishes prefer acidic water, of no detectable nitrate, and elevated temperatures (the low to mid 80's). Please see here: http://www.wetwebmedia.com/FWSubWebIndex/serrasalminae1.htm
I would address the water quality issues... You should see the "redness" disappear with more suitable environment. Bob Fenner>
Mike Williams

120 for Pacu
Hi Bob,
I love to see all the questions and answers on the site. One of my tanks is a standard 55 gallon freshwater tank. While most of the fish in the tank seem pretty comfy with the size of the tank, I do have two monsters that have out grown it. One is a silver Pacu who is about 12" long (big enough to fillet or walk on a leash) and an algae eater who is 14" long. I want to build a bigger tank for them to roam in. I was thinking about a 120 gallon acrylic tank.
<The Pacu will quickly outgrow this, too. These are true monsters getting over three feet long.>
What are you thoughts on this. Also, what would be the critical info on building a tank of this size (length, width, height, thickness...). I'm sure you know what I am asking. Any and all info you can give me as well as links to other sites would be greatly appreciated.
<Do take a look through the FAQ on building tanks here http://www.wetwebmedia.com/diytksfaqs.htm>
Thanks, Marcelo
<You are welcome. -Steven Pro>

Follow-up to Piranhas and Pacus Oh My!
Anthony:
<You got Steven pulling his shift answering some of the daily mail.>
Thanks for your input...I appreciate it! Can you tell I'm just a tad on the obsessive compulsive side? he he I'm glad to hear that I don't need to be so worried about the pH levels and can relax a little. I do have a couple follow up questions on the Pacu. Don't these fish grow to the size of the tank? From what you're telling me they'll just grow and grow and grow until they basically die (if the tank is too small).
<It is not quite true that fish grow to the size of their tanks. Freshwater fish are a little easier to stunt their growth, but that is not healthy at all. How would you like to live your whole life in your closet? Get the picture.>
How big of a tank do you need for a Pacu?
<For any large fish, find the maximum length. The tank's width should be twice the maximum length of the fish and the tank's length should be four times the maximum length of the fish. And remember that this is a minimum. For a Pacu, 4 foot wide and 8 foot long and probably 2 or more feet deep.>
I'm not necessarily "married" to the idea of getting one so I'm open to alternatives. Can you think of any? The Pacu is the exact kind of fish I'm looking for: a freshwater fish, grows very fast, grows very big and won't attack you if you put your arm in the tank! I've tried Oscars in the past but had terrible luck with them as they always got some kind of disease (ich, hole-in-the-head, etc.). I can't think of any fast growing, large freshwater fish other than Pacus and Oscars so that's why I thought I would consider a Pacu. Any suggestions?
Travis
<Generally, Oscars are a great fish as long as you keep their water clean with frequent, large water changes and good filtration, house them in an appropriate sized tank, and feed them a varied diet (no feeder fish). There are many other cichlids that meet you request, but they all have the same captive care requirements as above. Kind regards, Steven Pro>

Piranhas and Pacu (Oh! MY)
Robert:
<Anthony Calfo in your service... Bob has superglued himself to a piece of coral...strike one on his first foray into coral propagation>
Thought I would give you an update and ask you a few more questions, if you don't mind. It's been over 6 weeks since I've had the tank set up and the Piranhas are doing fine - despite the fact that I have yet to get the pH down to their ideal range: 6.5 - 7.0 The tank has reverse osmosis water in it so it's very soft (85 ppm) so I would think that the pH would adjust fairly easily, yet it won't go below 7.6!
<what is the total hardness of the water coming out of the R/O unit and has this number been confirmed with another brand of test kit?>
It's a mystery to me why the pH won't budge.
<85ppm is soft...but not extremely soft assuming that the test kit is accurate and not reading a bit low (which could explain the resistance)>
The tank has been up for a while now and according to what I've read, all established tanks will see a decrease in the pH levels as this is a natural process.
<agreed and inevitable for most>
I've also read that the softer the water, the less buffering and therefore the easier it is to adjust pH levels.
<yes>
Maybe 6 weeks isn't long enough and maybe 85 ppm is still too hard of water. Any ideas on what's going on?
<you are correct on both counts...but don't be obsessed with the low pH and soft water unless you are trying to breed them. The other side of the coin is that very soft and very acidic water is VERY unstable and quite frankly dangerous with the slightest slip in husbandry (overfeeding, delayed water change, etc)>
I'm going to be setting up an 125 gallon soon and will have a Pacu in that tank.
<the tank is still not big enough...quite frankly, I hope that you don't buy the fish. It's an inappropriate animal for most tanks growing to over two feet in length. Cruel to let it stunt and die prematurely (a few years old) as most do>
My research indicates they like the pH levels even lower: 4.8 - 6.5!
<too dangerous for captive aquariology unless you are research strict about maintenance>
If I can't even get my 55 gallon to a neutral pH...how am I possibly going to get an 125 gallon to a pH level of 4.8 - 6.5 ???
<my friend, have you considered drinking alcohol? Relax, goombah. A pH around neutral is safe and reasonable for such hardy fish and will serve you well considering the waste load they produce and potential for disaster at low pH/unstable soft water. If you are willing to go to such great lengths for water quality... breed wild caught discus instead and at least make money for your pains...hehe. Kindly, Anthony>
Travis

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