A few questions for Neale... Silica sand use in FW, Goldfish sys.   1/25/08
Hi Neale,
<Nicole,>
Hope you are doing well!
<Yep.>
I thought I would ask you, since I have heard you say before that you use silica sand (aka silver sand, aka pool filter sand) in your tanks...have you ever heard of any problems arising from goldfish being kept in an aquarium with such a substrate?
<Goldfish love sand! Your main problems are these: [1] Sand doesn't hide faeces the way gravel does. Faecal matter in tanks with gravel sinks between the grains, where you can't see it. It doesn't go away, but at least you can't see it until you stir the gravel. In a tank with sand, faeces sit on top of the sand. If you have a strong filter, they'll get sucked into the filter, but otherwise it can look messy. I find "spot cleaning" with an old turkey baster a great solution. If something looks too yucky, suck it up, and dump onto a houseplant. Problem [2] is that Goldfish can kick the sand about when they root about for food. They're happy as the proverbial pigs, but if the filter inlet is too close to the bottom of the tank, you can end up getting sand in the filter.>
My friend tried using sand but missed his undergravel filter, so he's giving me 50# of silica sand, and I was considering using that for my future 30 gallon semi-planted goldfish tank. I have read - admittedly, on forums of questionable repute - that this can be problematic, causing intestinal impactions in the goldfish due to swallowing mouthfuls of sand when they are rooting about in the gravel, and have also heard it can irritate their gills as it passes.
<Neither of these sounds likely. For a start, these fish live in muddy environments where they routinely throw all kinds of muck through their gills. But from my personal experience I've see smaller fish such as Corydoras and gobies thriving in sandy tanks, let alone massive great things like Goldies.>
Would you know if there is any truth to this? I suspect there is not, but if so, my next choice would be organic potting soil with a layer of fine gravel on top, since I have read that soil can be a fine substrate for a planted tank.
<Potting soil is rich in nitrate and phosphate, so tends to cause problems with algae. I do use pond soil in aquaria, which is formulated to be nitrate-free, but plain vanilla loams and soils tend not to be recommended. A better choice is coir (coconut fibre) which is relatively inert but looks very nice. Your problem here is that as much as the fish love this stuff, it makes the water completely cloudy *unless* you have teeny-tiny fish such as killifish that can't root about.>
I have silica sand on two of my tanks, and I notice that (for me, anyway) it does seem to encourage smudge algae, or brown algae or diatoms - whichever it may be! This is fine since both tanks have a trio of Otos, and they seem to relish the stuff, but I am nervous about keeping Otos with goldfish, so I'll just have to step up on the water changes and do two 30% changes weekly.
<The jury is out on whether silica sand genuinely creates a diatom bloom or not. Here's the issue: silica sand is basically glass, and both are effectively non-soluble. The amount of silicon coming out of silica sand will be completely negligible if the chemists are to be believed. My thinking is that silica sand is more difficult to clean than gravel, so perhaps more silt gets in, and *this* promotes algae. Perhaps also the brighter colour of silica sand makes algae more obvious. Finally, it's worth mentioning that all new tanks get diatom blooms; it seems to be part of what happens when you set aquaria up.>
My plan is to keep 2 shubunkins, and a Synodontis eupterus together in the 30 gallon tank. I know this is woefully small for the Syno, but he is still "only" 6 inches and he is moving to a 55 gallon tank by the end of the year. If the shubunkins ever get too large where maintenance becomes impossible, the same friend who is giving me the sand has a natural clay lined pond that already has a couple of full grown comets in there.
<Hmm... some Synodontis are confirmed fin-nibblers, so do your research here carefully.>
I plan on massively over filtering the tank: hang-on back, 330 gph filter rated for 60 gallons, plus a Penn Plax 115 gph canister filter rated for 30 gallons, with a spray bar, and chock full of sponges and ceramic noodles. The hang-on back filter will contain filter floss contained in 800 micron media bags. The floss I plan on rinsing weekly and replacing monthly. Does this sound all right?
<Sounds great. The more you rinse the floss, the less often you actually need to replace it, by the way.>
The plants I intend to keep are a few of the inedible kinds - Java fern, Java moss. Some regularly thinned Salvinia on the top, and Water Wisteria in the substrate. I plan on trying Elodea/Anacharis but I suspect it will be chomped on heavily.
<Elodea = goldfish food.>
Is there any benefit to adding a thin layer of Laterite (20 oz.) and pouring the sand on top? (That is, if the silica sand is acceptable, of course.)
<Laterite mixed with fine gravel, and then topped with sand (with a gravel tidy between the two layers) works very well. It's a trifle old school, but serviceable.>
I would really appreciate your comments, and any advice, since I am a planted tank newbie. I have never had luck with plants; I do realize now that lack of lighting has been the reason, along with being sold houseplants. I know better now! My water is very hard and alkaline (alkalinity is off the charts at 300 ppm on my test kit) and I am lucky enough to be on a well, so no need for dechlorinator either.
<Goldfish love this kind of water.>
The city water I had before this was dreadful, very low in alkalinity.
Fishkeeping is loads easier now, it almost felt like you were speaking to me directly when I read your hard water article! I've been meaning to try some fish that would really appreciate the hard water and plant combination, I am hoping that the goldfish will.
<You get it! Yep, everyone thinks hard water is a bad thing. It's actually a blessing in disguise, once you understand how aquaria go wrong, and what it is water hardness actually does to help.>
Thank you so much for your time. Also, your article about fish for a 10 gallon tank was superb! I suspect you had lots more to say, but had to keep it concise due to space constraints. I am definitely keeping it sandwiched in my aquarium books for future reference.
<Glad you enjoyed the article! Yes, there is a lot to say about the topic of choosing the right fish for a given aquarium.>
Take care, and thanks again!
Nicole
<Happy to help.>
P.S. By any chance, do you remember what kind of Synos these were?
http://en.wikipedia.org/wiki/Ram_cichlid
I noticed you were the author of this stunning photo! The sand looks beautiful, I've never seen such a lovely yellow color, although I am guessing it's a trick of the light and it's really silver sand...
<The sand does look very yellow under certain lights, especially if you have some bogwood in the tank tinting the water brown. Those cats are Synodontis nigriventris, a nicely-behaved small, schooling Syno ideally suited to community tanks although it is one of the fin-nibblers, so you do need to watch it carefully if mixed with slow-moving fish.>

Aggressive goldfish... just too crowded, not reading   1/7/08
Hello! I'm KJ! First of all, thank you for having such a helpful site, I have really learned a lot from it!
<Ah, am glad KJ>
I have a question about my crazy goldfish (they aren't actually crazy, it is probably more that I'm crazy about them).
<Insightful>
Anyway, I rescued two goldfish, a comet and a fantail, from my swim team's coach's office over the summer. I became very attached to them, and wanted a better home for them than a small bowl. I don't know exactly how many gallons were in the bowl, but I *know* there was no way any number of fish should have been in it. So, for a Christmas present, my parents gave me an Eclipse 12 Gallon tank (Yay!) that I planned on moving my two lovely fishies into. However, a week or so before Christmas, I noticed symptoms in my fantail that resembled dropsy (I've had a beta fish die from it as well). I tried to help him/her, but I think it only extended his life a little.
Sadly, he died on Christmas Eve. So I set up my new tank on Christmas morning, and my parents were ready to move my yellow fishy, as I call my comet, into his new home. I made them wait three days to let the tank mature a bit, because that was the time most people suggested.
<Need more time than this...>
Before I woke up on the 28th, my parents ran out to Petco to surprise me and bought FIVE new fish, 3 more comets (all very small, about 3/4 o f an inch), a red-cap Oranda, and a calico fantail. The largest fish in the tank is yellow fishy, my old comet, but only by about a quarter inch.
<Yikes... the 12 gallon isn't large enough for one goldfish in time...>
So the whole point of that story is that today, I was procrastinating from my homework and watching my lovely fish when I noticed that the calico fantail had the uppermost right tip of its tail missing. It doesn't look like rot, I already checked that out, but it looks like it was cut off. At first I suspected the pump that draws water into the filter, but I looked into my tank with horror as my beloved yellow fishy was nipping the fantail!
<Yes... too crowded>
So, I have removed yellow fishy, and put him in his bowl (only temporarily, of course). My main question is, however, even though there are too many fish in one tank, why did my yellow fishy only go after the one fantail?
<Crowding... easier target>
And he has more room than in the bowl with my old fantail?! How should I deal with my yellow fishy and my calico? He really just ignored the other fish in the tank, but he chased the poor fantail... Oh, and should I treat the calico's tail?
<Mmm, indirectly... by making more room...>
In some earlier responses, it says to treat for fin rot, but others say just to watch it and keep the water clean.
I really hope I haven't wasted your time and I appreciate your response.
Why can't we all just get along? :)
KJ
<For about the same reason/s... Please read here: http://wetwebmedia.com/FWSubWebIndex/gldfshsystems.htm
and the linked files above. Please follow directions and look before writing us. Bob Fenner>

Re: Aggressive goldfish... lack of values   1/8/08
Thank you for your prompt response, but I believe you misunderstood me.
I know and understand that there is not enough room in my tank for so many fish. I guess I did not make that clear. However, I did not buy my fish, my parents bought them for me.
<... I understood/stand this... nonetheless... what will you do?>
As four of them were apparently only 29 cents, I would feel stupid asking to return them. In addition, I did not buy my tank, it was also a gift, because I only have a summer job as I am still in school.
<... impertinent>
My question was more along the lines of why my fish disliked only one of his tankmates, not whether my tank was too crowded or not.
<It... fishes... don't dislike anything (at least to my perception), but many are rather autistic... do "pick" on things that are "in the way">
I did read your site, I know I have too many fish, but I cannot do anything about it at the moment.
<Then your fish will suffer and die>
Also, most questions that involved aggressiveness in goldfish involved multi-species tank, and I have only goldfish.
In an email dated November 25, 2005, it was the opposite situation, with a fantail bullying a comet, but they did not mention tank size. I find it slightly offensive that by providing more information I received a rude reply with no answer to my question.
Again, I still like your site, and maybe you were just in a bad mood.
*I really just want to know how to keep my fish safe*. I cannot afford a larger tank, and I do not want to offend my parents by asking them to return my fish.
<... then... see the above. RMF>

Goldfish stunk up house... 12/7/07
Hi there,
<Ave,>
I moved out of my old house that I shared with a roommate just one week ago. She had a 10 gallon tank with just two goldfish, I bought two goldfish and one Plecostomus.
<Hang on... three Goldfish and a Plec for a 10 gallon tank? Whoa... too many fish. These four fish will need something like a 55 gallon tank to even begin to be kept sensibly. Goldfish get large -- 20-30 cm depending on the variety, and the Common Plec easily reaches 45-60 cm in captivity.>
The fish lived together for about 6 months. Anyways....I bought a 10 gallon tank of my own, and took my three fish. I set up the tank and put them in right away. I also added water conditioner...nowhere in the instructions to my Aquarium Start Up Kit did it say that I needed to wait a few days before adding the fish (which I just learned from your website).
<You don't need to "wait a few days". Nothing magically happens. It's not like waxing a floor. Tanks need to be CYCLED before use. You can do this with fish or without fish, but either way it takes several weeks. Putting Goldfish into a 10 gallon tank is a bad idea though.>
Now, we've noticed our house smells like cat-pee...only problem is -? We don't have a cat!!?
<Not the fish either. A healthy fish tank is odorless as far as the average person is concerned. Fish tanks only smell if they're full of dead, rotting things... in which case the fish probably shouldn't be there either. So let's review: how large are the fish? What filter are you using? How often do you do water changes? How much do you feed the fish?>
I know that goldfish put off ammonia...but I've never smelled it before.
<They don't produce ammonia but ammonium, and in very small amounts. It dissolves in the water. The concentration is so low you cannot possibly smell it. As any Sushi chef will tell you, the "fish smell" westerners associate with fish is actually the smell of *rotting* fish and nothing at all to do with healthy live or freshly-caught fish.>
Maybe the move stressed them out, (and they miss their friends?) and now they are dispersing this awful smell???
<No. I think your imagination is running away with you a little here. If your fish tank smells, it's because you're not looking after it properly, in which case your fish are FAR MORE UPSET than you are!>
What do I do...I like the fish...but I refuse to let them stink up my house.
<It's the fish's home that stinks, and the reason is likely you. Don't blame the fish.>
Please email me back...they'll have to be flushed or given back to Petco if I can't resolve this.
<Natalie, tell me the "flushing" statement was a joke. No-one with any conception of animal welfare would flush a live fish down the drain simply because they couldn't be bothered to care for it anymore. The amount of bad karma there would be enormous and you'd be at grave risk of coming back as a slug or something in your next life. Caring for animals is all about finding out what they need, and then providing those needs. Goldfish don't require a huge amount, but those things are non-negotiable. We have lots of articles on Goldfish, including some simple primers for inexperienced fishkeepers:
http://www.wetwebmedia.com/FWSubWebIndex/gldfshsystems.htm
http://www.wetwebmedia.com/FWSubWebIndex/goldfish101art.htm
Do also remember your Plec is a TROPICAL fish and needs a heated aquarium. While Goldfish will tolerate warm water quite well, they will not thank you for being kept above 24C/75F.>
Thank you very much for your time! :)
(Natalie)
<Hope this helps, Natalie-in-parentheses for some reason.>

Re: Goldfish stunk up house... Myths, Rudeness...  12/07/2007
Hey there,
<Hello Natalie,>
Apparently you didn't read my email very well... I have two tiny goldfish (about 1 1/2 inches each) and one small plec about (3 inches).
<You don't have tiny fish; you have baby fish. Very different entities.>
(Fish grow depending on the space they're given...they CAN grow large...but I don't want them to...so I'm not going to give them a huge space in my house.)
<Fish DO NOT grow to the size of the tank they are kept in. That's a myth. Feel free to read up on the subject. Some large fish species kept in fish farming become stunted, such as salmon and carp, when kept in overcrowded ponds. But very few of the aquarium fish sold today do this. Fish are not bonsai trees, and nothing you can do, beyond starving them, will have much impact on their growth rate. And if you starve them, they'll die anyway.>
it's not a heated tank, but I have a proper NEW filter, and light and watch the temperature and adjust it as needed.
<Watching the temperature is fine, but Plecostomus-type catfish need a minimum temperature of 22C/72F to do well. Below that, they generally become sickly and die. Go visit Florida where Plecostomus catfish have become established in the wild. They are limited to the southern part of the state because they need constantly warm water. If they could manage at room temperature, they'd be halfway across the Union by now, settling into Lake Michigan. But they're not, because they aren't coldwater fish. Period.>
I highly doubt that they'd need a 55 gallon tank - sounds quite absurd...goldfish live in bowls in many homes for heaven sake.
<No, they don't live. They linger, and then die. Quite different. Goldfish can live for 20 years easily, and much more than that given proper care (the record is 45 years). Find me a Goldfish that has lived in a bowl for 30 years and reached a healthy size, and I'll eat my hat.>
Also...you said I wasn't taking proper care of the tank and it was my fault it stunk...dude...you really didn't listen - cuz I wrote that I bought a brand new tank, set it up and put them in it...how could it possibly have time to grow algae and become dirty and smelly?
<Well, you aren't taking proper care of these fish. For a start, they're in too-small a tank and the tropical catfish isn't being provided with heat. Fish tanks that are properly cared for don't smell. I have three in my home and they don't smell of anything. I've kept fish for 20+ years and never smelled anything. I've worked in universities, marine biology labs, and museums with fish tanks... and guess what, they never smelled of anything. Bad smells come from decay. If there's something decaying in your tank, then you aren't looking after it properly. QED.>
in just a few hours??? Plus...if you stick your nose up to the door (that you open to feed them) it smells like ammonia - or ammonium or whatever.
<Then there's decay in the tank. Identify the source, remove it, and move on. Water with 0 milligrams per litre of ammonium in it doesn't smell of anything. Even water with a lethal amount of ammonium, say, 1 mg/l, won't smell of anything. Dead fish smell, and maybe decaying fish food. But not a properly run aquarium.>
( Don't try to make yourself feel smart - by pointing out the difference between the two...because it obviously smells the same.)
<I don't need to make myself feel smart. I am smart. I have a Bachelors in zoology with first class honours and a PhD in palaeontology. I write for all the major fishkeeping magazines and I've written an aquarium book as well as books on other topics. I've been an expert on BBC television, a university lecturer, and a museum exhibits designer. I've been featured in newspapers articles, magazines, and even political cartoons. Just last night I finished grading undergraduate papers for the history of science class I teach for Pepperdine. So I am smart, and I really don't need to feign smartness, and certainly not by being mean to people asking for help. So... instead of getting defensive and mean, have a listen to me trying to offer you help. I'm taking time out of my day to tell you where you're going wrong and what you need to do to fix things. Of course you don't have to listen to me, but if you think you know better than me, let's just say you're probably mistaken and I suspect your fish would agree.>
Oh, and no...the flushing statement was not a joke... but I probably would just take them to Petco...although flushing would be easier. ha ha.
<Hardly ha-ha for the fish, and also illegal in most places because of the risk of non-native wildlife escaping from drains during floods, etc. Cruelty is cruelty, whether you decide to face up to that fact or not.>
It's not a dog...it's just a damn fish.
<So? The weight of scientific evidence is now that fish do indeed feel pain, even if not in quite the same way as birds and mammals. You can rationalise this away if you want, but the scientists studying the issue increasingly believe fish feel pain. Again, feel free to disagree if you're a neurobiologist, but if not, why not listen to the science instead of acting out of ignorance.>
I am quite the animal lover (believe it or not)
<Sorry, don't believe it. Being an "animal lover" doesn't mean much if all you do is give dogs cute names and buy posters with dolphins on them to decorate your bedroom. Animals don't give a rip about that sort of stuff. What animals want is to be treated properly. And that invariably means stuff giving them adequate housing, providing the right diet, keeping their environment clean, and ensuring they are sufficiently warm.>
I may not be some crazed hippie, who thinks that goldfish have personalities, and you can talk to them and train them, and spend "quality time",
<Again, you're way off base here. Goldfish are widely used in animal behaviour experiments precisely because they respond well to training. They have quite good memories for example, remembering tricks up to 3 months after last using them (rather better than the average dog). They are also able to learn to recognise different humans, learning which ones feed them and which ones don't. And yes, they do have "personalities" of a sort, with each school of Goldfish having dominant and sub-dominant individuals. This is all science. Not crazy hippy stuff.>
seriously dude...I don't know whether to tell you to take your job more seriously (by actually reading people's letters...as simple as me saying I had two goldfish, and one plec...then you came back with that I had 4 fish...what is that, like 1st grade math?)
<An easy mistake. I misread something. So what? Doesn't make any difference at all. You have too many animals in a too-small aquarium.>
or less seriously (cuz it's just a damn goldfish - and they're fine....get a dog or something - with a personality, a being that can actually interact with you, so you won't feel so alone in the world...because I'm quite sure that you are)
<I'm sorry, this sort of thing just makes you look like a jerk. I'm the guy writing back to you trying to help you look after your animals better. You're the guy writing mean-spirited e-mails trying to defend the fact you aren't looking after your animals at all well. I'm the guy who, out of desire to help others, spends an hour a day answering people's questions without getting paid for it. You're the guy who's telling me you don't care about animals and would happily flush them away because you they're too lowly to worry about. I'm the guy who cares about animals by doing something constructive; you're the guy who says they care but is actually too cheap to provide the space and heat her livestock requires. Who'd you think looks like the person more likely to be alone in this world?>
Happy Holidays
<Likewise, Neale.>

Goldfish... sys.  11/25/2007
Hi WetWebMedia,
About six months ago, I rescued three goldfish from a county fair. The goldfish started out about 3/4 of an inch a piece. They are currently living in a 10 gallon tank with a GREAT filter. However, my goldfish are rapidly growing and are now about 1 1/2 inches a piece. (One is closer to two) I realize that even with great filtration, a 10 gallon tank is not enough, however, my goldfish are still somewhat small. I am in the market for a new tank, but I don't know what size to buy. I was considering a 30 gallon. Would this be enough to house my goldfish? I really don't have room for anything larger, and I read that 10 gallons per adult goldfish should be adequate. I'm not quite sure on the species of the goldfish, they're just the regular kind they give away at fairs. Do you think a 30 gallon would be good? Also, what size filter should I buy, because goldfish are quite messy? (Right now I have a 20 gallon filter for my 10 gallon)
Thank you for your help!
-Carly
<Hello Carly. A 30 gallon tank would be perfect for your Goldfish. 10 gallons per Goldfish is too little space: these fish get to at least 20 cm in captivity, and potentially more than 30 cm. So A good rule of thumb is to set aside 30 gallons for the first Goldfish, and then another 10-15 gallons for each additional Goldfish. Some people would recommend more space than that, and I certainly wouldn't disagree with them. Goldfish are schooling fish and like to be kept in groups, at least a pair. The more is definitely the merrier. Instead of the fish just sitting there, as tends to happen when a single specimen is kept, pairs and trios will constantly play around, chasing each other. To some extent it depends on the variety; fancy goldfish (i.e., fish with twin tail fins) are less active than regular goldfish (i.e., fish with a single normal tail fin). Comets and traditional Goldfish are active swimmers, and the more space you give them, the better. Length of the tank is more important than depth, so if that's a factor when choosing between tanks of identical volume, go for the longer tank. As for the filter, ignore what's written on the box: manufacturers are often rather vague and/or optimistic when writing that stuff! Instead, look at the turnover of the filter. This is a measure of how much water goes through the filter. You want something that provides a turnover of not less than 4 times the volume of the tank, and ideally 6 times. So if you had a 40 gallon tank, then a filter that was 4 x 40 = 160 gallons per hour in size would be the minimum, and a filter 6 x 40 = 240 gallons per hour would the ideal. Simple as that. This number will be printed on the box somewhere, and is usually provided by retailers on their web sites as well. You don't have to use just one filter, you could simply buy another filter to go with the one you have. So long as when added together they provide enough turnover, you're fine. Cheers, Neale.>

Sick goldfish in a small aquarium  10/14/07
Hi guys wonderful help site,
I have a celestial goldfish about 1 and a half months old. He lived by himself in a 2.5 gallon tank until today when he received a friend, another goldfish. When I was putting the other goldfish in the tank I noticed that he has a red spot on his stomach and he continually swims around on his back with his stomach on top of the water. Then I noticed that he has a small red spot around his left eye also. I change half his water every 1-2 weeks and feed him regularly. I have not tried to treat him with anything yet for fear of making it worse but i continually flip him back over when he is on his back with his net. He is not lethargic or hyper, and does not exhibit any abnormal behavior except he continually tries to swim behind his filter an in the process flips himself over again. Please help me I would hate to have him die without at least trying so save him.
Thank you for your help.
<Greetings. For a start, your tank is too small for Goldfish. A 2.5 gallon tank is really just a bucket with a fancy name. Indeed, I have buckets twice this size just for doing water changes. Imagine I locked you up in a small automobile, and the space inside there was not just where you lived and exercised but also your kitchen and bathroom. How long before you got sick? That's where you're at keeping a Goldfish in a 2.5 gallon tank. Long term, Goldfish need a 30 gallon tank, minimum. Failure to do this ends up with sick fish -- you will find it very difficult to provide the good water quality these fish need in such a tiny space. The red spots are likely early-stage Finrot or fungus. These are classic symptoms of poor water quality. Check your ammonia and nitrite levels; if they're not exactly and precisely Zero, you have a problem. Changing the water IS NOT A SUBSTITUTE for having a proper filter. You HAVE TO DO BOTH! Next up, the "floaty, bloaty" goldfish likely has swim bladder problems. This usually follows on from people failing to give a Goldfish its correct diet -- PLANTS! Giving them just flake food = sick Goldfish. Simple as that. So, please have a read of these two excellent articles, and then see what you can do to improve the lives of your pets: http://www.wetwebmedia.com/FWSubWebIndex/gldfshsystems.htm , http://www.wetwebmedia.com/FWSubWebIndex/gldfshmalnut.htm . These animals depend on you to do the right thing; if spending the time and money on their requirements is too much for you, then don't keep animals as pets. Keep

Goldfish in what was a Marine aquarium.... 10/3/07
Hey guys, I've enjoyed reading many of your responses to other fishy people during my tenure in reef keeping. I have decided to go freshwater, fancy goldfish in particular. I have a 55 gallon drilled tank and a 20 gallon sump. I have emptied the tank, sold the skimmer and now I'm wondering if I can keep the sump in the new setup. I was thinking of adding large gravel and aeration to the tank and a U/V unit and bio-balls to the sump in place of the skimmer. I also have a filter-sock in the sump. My goal is to incorporate as much of my old setup as possible. Am I on the right track, perhaps you could suggest a better use for the sump?
Thanks in advance,
Keith
<Yes, all this is fine. Standard skimmers stop working between about SG 1.010, so while useful in brackish water tanks they won't work in freshwater. The UV and sump will both work fine. Your only concern will need to be with water movement. While goldfish appreciate relatively high levels of water turnover (around 6x the volume of the tank per hour) fancy goldfish are not strong swimmers. So you need to balance turnover against current. As a general rule, the "hardy" fancy goldfish, like black moors, are more adaptable than the "flimsy" fancy goldfish, like bubble-eyes. Good luck, Neale>