? About Fancy Goldfish

[Darkwynd]

I have a 10 gallon tank, currently being used as a pl*co growout tank, that I am trying to decide what to do with long term. One of the fish I have been looking at getting (in general, not specifically for this tank) are fancy goldfish. I know you are supposed to allow 20 gallons a piece for fancy goldfish, but how long could I reasonably expect to keep 1 or 2 fancies in a ten gallon before they got too big if I got them when they were 1-2 inches? Would I just be asking for trouble to even try it?

[ohmar606]

I did that already had to do alot of water changes, I think you are setting yourself up to fail becuase i could not even properly enjoy them.
finally the whole system crashed and my goldfish died,

[Bedlamer]

10 Gallon Goldfish

It’s always nice to have an extra 10 gallon around as a quarantine or hospital tank. If you are specifically looking to keep goldfish you would be better off starting off with a bigger tank. That being said, yes, you can keep small fancy goldfish in a 10 gallon tank quite successfully for quite awhile. I started very unsuccessfully with keeping fancy goldfish in bowls when I was a small child. I kept an aquarium as a teenager and had 3 small tanks going when I was in university, quite awhile ago. One of those tanks included a 15 gallon tank with an Aqua Clear 50 HOB. I had a 3.5” inch fork length Black Moor, a 1.5” Red Cap Oranda and a 1” Calico Moor. I always did weekly 80% water changes with heavy gravel vacuuming. I would say in retrospect the tank was overstocked, but it worked with regular maintenance. Had that running for about 10 months I sold the tank and the fish when I moved, so I don’t know how that worked out in the end. I can only hope the guy kept up the large water changes and maybe got them a larger tank.

Last fall I decided to get back into the hobby. What I had on hand was a 10 gallon tank and 2 Aqua Clears, a 50 and a mini. I was thinking of getting a few tetras maybe. I read a bunch more fish books and I spent four weekends going to all the LFS on the map on this forum. In the very last store there was a tank of Panda Moors. I had only seen pictures of them before that. I had 10 gallons of aged, dechlorinated water sitting on my kitchen floor. After fretting and hemming and hahing for quite awhile strolling around the store, I decided I just had to have them. I had them bagged up and stopped at the local Pet Smart on the way home and picked up a Calico Moor that I had been looking at for a couple of weeks. That was October 7th, 2010. All of the fish started off at the same size, very small—fork length around 3/4”. I eventually added a medium sized Mystery snail. I do weekly 80 % water changes with gravel vacuuming and test for ammonia and nitrite before I do. I started off with just the Aqua Clear 50 running. I added an Aqua Clear mini and a tiny TOM internal filter afterwards—mostly to have ready to go cycled filter media for other small tanks. If the manufacturers claimed flow rates can be believed my gold fish tank has 34.5 turnovers per hour. I eventually ditched all my carbon and replaced it with Bio Max pellets. After the tank completely cycled I have never had detectable ammonia or nitrite, even when I have taken media from the smaller filters --except for one unfortunate day I had turned all the filters off to mess with the tank, then forgot to turn them on and left the house for about 12 hours. On my return, all three fish were gasping at the surface, one on its side. Many hours and several 50 % water changes later that was sorted out. The point there is that with such a heavily stocked tank in a small water volume there is little margin for error. One lengthy power outage would be a bad thing. Also Aqua Clears can either stop or slow unexpectedly if some gunk builds up or gets stuck in the impeller chamber. The smaller ones especially may fail to re-prime after a power outage – so unless you are running a very reliable filter system like a good canister, you might want to add an small auxiliary filter for a redundant back up. Today the fish are 3”, 1.75” and 1 .75” and the Mystery snail is size large these days. They get one large feeding of dried food per day, plus the occasional treat of peas or zucchini. All of them are very robust and healthy and still seem to have a decent amount of swimming room. It is the most stable tank I have, and have next to no issues with it—and I do properly enjoy them, and have been for close to 9 months now. All that being said, I already own their next tank upgrade--a 29 gallon with an Aqua Clear 110 HOB—I’m just waiting for my buddy to finish painting the back of it for me. I guess another year from now I’ll be looking at a 65-90 gallon tank for them.

Now something you may not have considered is this…goldfish can radically change their coloration and even morphology as they age. The larger and (therefore older) the goldfish you purchase—the more likely they are to remain looking moor (pun intended) or less the way they did when you got them. This is a good argument as to why you should start off with larger goldfish in a tank much larger than 10 gallons. They can live 20 plus years (the fancy ones usually quite a bit less on average)—so you may be looking at them for quite awhile. My Calico Moor’s body shape has changed quite a bit (he is the fastest growing one) and his tail fin has even become much less elegant in its shape. Both of my Panda Moors have lost most of their black coloration and one is developing orange where the black used to be. The 3 most common theories I have been able to find to explain these changes are nutritional deficiency, lack of exposure to sunlight, and poor genetics. For reasons I won’t go into here, I believe in my case my fish had poor genetics—which might have been avoided if I had waited, gotten a larger tank and larger fish.

The old rule of thumb of 1” of fish/gallon for tropical fish doesn’t apply to goldfish (one inch of tetra is a lot less bio mass than one inch of fancy goldfish, and they are gluttonous little vacuum cleaners with fins—I love my fatty fishies—lol) I’ve seen another rule of thumb for goldfish as 20 gallons for the first fish with 10 gallons for each additional fish ( which even with my upgraded tank I won’t be achieving but seems reasonable to me), also to drastically increase the amount of filtration from the usual recommendations for small tropical fish.

Some time ago I read the online question (not this website) from a little girl if it was OK to have a single small goldfish in her 10 gallon tank. What she got back was a bunch of vehement hatred directed towards her along the lines that she was a reprehensible fish abuser for even thinking such a thing (I was wondering how many of those writing in routinely used feeder fish) and she should start off by digging a koi pond, and making sure that her second husband was going to be cool with her having fish—I overstated the last bit for effect—but not by much—I thought it was a bit of overwrought demands for a life commitment for a budding aqauarist’s first attempt. I really wanted to reply to that question—but the comments were closed—thus my long winded response here.

So in closing I would answer your question as can it be done? Yes, with a lot of filtration and routine huge water changes. Well, for awhile at least. Should you do it? No. There are better things you can use that 10 gallon for. Start off with a bigger tank, a good filter, and older/larger good quality livestock for your fancy goldfish aquarium.