I'm kinda in a panic, recently (as in yesterday) a co-worker who knows I have a fish asked if I would adopt her son's goldfish. In true fish-addict fashion, I said yes. Only problem is that the only time I've ever had a goldfish it was a carnival prize and I killed it within days. Granted, I was seven, but still I have no idea what I'm doing when it comes to the most entry level of fish.
I get them in just under two weeks. Luckily I have a tank that is already cycled as I am moving my betta Beau to a slightly bigger tank at nearly the same time. But as far as food, water temp, safe toys for them, I'm completely lost.
For a fancy (round-bodied), the general stocking rule is 20-30 gallons for the first fish, an extra 10-15 for every additional fish.
For a common, comet or shubunking, 55-75 gallons for the first fish, 20 gallons for each additional. These guys really do better in ponds.
Fancy goldies do best in water 68-75, whilst comets are better in under 72F. They prefer hard water with a neutral to basic pH.
Pellets are best - flaked or floating foods encourage them to gasp at the surface, which can cause swimbladder problems. They like variety, so live food and green plants can also be added to their diet.
For toys, do what you would with a betta - make sure it can't rip their fins. Sand or large tumbled river rocks make the best substrate, as they can swallow gravel.
You need a very high-capacity filter (twice the capacity of the tank) as goldies are messy creatures.
They are social and prefer to be in groups.
They are amazing, beautiful and very rewarding fish, but they are also a big commitment and require an expensive outlay. That being said, once you have everything, maintaining them isn't so pricey. :)
I'd PM KoiMaiden and Olympia and ask them to weigh in, as they are goldie experts in this forum and can correct any mistakes I've made or add extra information for you. :)
I don't actually know what kind of goldfish they are, all she could tell me was that they are white. They were her son's before he went into the service, and she can't continue caring for them. I do know that she is currently keeping them in a large peanut jar, so I'm kinda considering this a rescue.
Also, I know this is going to sound really bad, but I simply don't have room for a 25+ gallon tank. I live in a very small apartment, and before anyone tells me that I shouldn't adopt them, if I don't they will starve to death. My co-worker is going on vacation to Florida right after leaving the fish with me, but if I don't take them in, they will be left in her house for two weeks without food. (She already refused my offer to stop by and feed them) These little guys are in an all around bad situation, and I at least will be able to give them a clean tank to live in.
I have done a little research, mostly before I got Beau, and I know that a fish will only get as big as it's environment allows. Granted I have not seen the fish yet, but as the four of them are in a peanut jar and have space to move around, I don't believe that they are huge. At most I expect them to be 2" or so.
I'm not saying don't adopt them, but I am saying that you should look for someone else to take them long-term.
The restricting factor in goldfish size is not tank size. In a small tank, as you know from betta-keeping, ammonia builds up, as do hormones released by the fish. This is what stunts their growth - painfully and dangerously - not the size of the tank. If you keep the water sparkly clean, they will grow to their predetermined size. That's a minimum of 6 inches for a fancy, and 12 for a comet.
It is great that you want to rescue them, but please consider looking for a home for them with someone who is able to care for them. Until you can, you are looking at daily 75% water changes to keep ammonia levels under control, as goldfish have an enormous bioload.
The frequent water changes don't bother me, I'm already doing daily 50% as I'm treating my betta for tail rot in an unfiltered tank. (We're almost over it!) And I do a once weekly 100% to get the rest of the nastiness out of the substrate. I have also started caring for the fish in the classroom I work in, so I am completely aware of the huge bioload of goldfish. (Trust me when I started cleaning it that tank was nasty!)
I was also doing some reading up on goldfish tonight, and everything I'm reading says to not go above 60 degrees, as they are a cool-water fish.
I have done a little research, mostly before I got Beau, and I know that a fish will only get as big as it's environment allows.
Leeet me cut in right there. With this, from what I'd been reading - yes this is true, their bodies stop growing, but their organs do not stop growing. So yes one may have a 4" fish, but their organs may be that of a 6" or 7" fish - a very bad and painful way to die. I don't know if this is with all fish or just certain ones but it's something I've been taking into consideration big time with fish ever since I heard of it.
I do gladly accept being shot down on this, but this is what I know on stunting growth.