I have 2 comet goldfish in a fairly large tank and I have room for one more fish
I don't know where you got the idea 6 gallons was in any way large when it's barely big enough to cope with a betta.
YOU DO NOT HAVE ROOM FOR EVEN ONE GOLDFISH, LET ALONE THREE.
It's ok, I'll just live with what I have.
In which case your goldfish are not going to live for very long
at all. Your fish should not have to suffer to live with what
you have. As the owner it is your responsibility to provide that fish with the correct sized tank for it's species, and you are not doing this. By continuing to keep it incorrectly, and KNOWING you are keeping it incorrectly, you are causing cruelty. I'm not saying that to be harsh, I'm saying it because it is a basic fact.
Each fish requires 30 gallons minimum.
Absloute bare minimum, preferably 55 gallons or bigger for just
two goldfish. And I'm not talking normal goldfish, I mean fancy round bodied goldfish. Normal bodied varieties are pond fish. They get even longer than fancies. 14 inches is pretty normal.
To keep a normal bodied goldfish indoors
you need a tank at least 5 feet long for it to have room to grow , and swim up and down. They are vey messy, eat a lot and crap a lot. They require a big
external filter to be able to cope with all the waste they produce, and even then you have to do large regular water changes.
I know what your going to say. You're going to say something to the effect that your fish look fine, swim well, eat and are generally in what
you think is good health.
This will not last. You've crammed them into a tiny tank where they will not be able to grow, and you cannot attatch a filter that can cater to their needs.
By keeping those fish in a tiny 6 gallon tank, you WILL kill them eventually. Such a small amount of water and space will stunt the growth of the fish. And shorten their lifespan. Do you actually WANT to do that to a living thing? If the answer is yes then frankly I wonder at your sanity. You certainly cannot claim to care for the fish if you actually
want to do that to one. And that is what you are doing by keeping it in such a tiny tank.
Also, there is no filter in existance that will work on a tank that small to cope with the amount of waste a goldfish produces. I hope you're doing daily water changes to keep the ammonia levels at zero, if not, you are causing your fish to sit and suffer in their own crap. In their own waste. A bit like locking you in your own bathroom for the rest of your short life , and never opening the windows for fresh air. Sound good? No. Not really.
If by some miracle they do grow, they will outgrow their living space and be pretty much unable to swim more than a few inches or turn around properly at the end of the tank. In which case you will have no option but to get a bigger home. But by this point the fish will be suffering anyway. How do you feel about being the cause of that?
If you cannot afford a bigger tank, or have not got space for a bigger tank, then PLEASE, if you care anything for the fish, grow up, drop the
"mine mine mine I don't wanna give it up" attitude, and rehome the fish with someone who has the correct space for them, or take them to a store who can care for them. There is absolutely no need to make those fish suffer because you won't suck it up and do the right thing.
the only down side is that the females only give birth ever two months or so, a lot slower than warmwater guppies, but that just makes it even more exiting when they do have babies
