How many GOLDFISH can I have in 20 gal tank? Name fish in GOLDFISH FAMILY that could be put together to clean.?

Comfortably you can house 4 fancy's from pearscale, moore, Wakins, Jinkins, fantail, Ranchu, oranda, ryukins, demekin, pompoms, veiltail, egg fish, lionhead, celestial. Any combination and not more than 4 can live happily in a 20 gallon. If you are going with the pearlscale you can go with 5.

Unfortunately there are many miss conceptions of how much water a goldfish needs to be healthy and happy. one goldfish certainally does not need 20 gallons of water each. Fancy's are fine in 5 gallons each which is more than enough for swimming and proper growth. Only the larger species need not so much more water, more swimming room.

I am not sure what you mean by clean? but a pleco will also go well with these cool water fish as an algae cleaner.

In a twenty gallon tank I would say one fancy goldfish. Definitely don't buy any comet goldfish.

~Goldfish are very large fish. The common or comet goldfish reach about a foot in length, while the fancy varieties reach 6-8 inches. Nitrates build up easily in such a small tank, and inhibit growth. This stunting leads to an early death.

~The general lifespan of a common goldfish is 12-20 years. When kept in a small tank with insufficient filtration, they commonly live about four years. That is disgraceful for a goldfish.

~All types of goldfish are very dirty. They produce more waste than other types of fish. The waste they are constantly giving off becomes ammonia. In any amount ammonia is lethal to fish. The only way to avoid a problem with ammonia, is to have a very large tank, and an extremely efficient filter.

Eh, depends on the goldfish really. But for the most part, 20 gallons is usually too small for one goldfish.

http://www.flickr.com/photos/marybag/33503861/

Those goldfish arent even done growing yet. They could still double that easily. Goldfish get extremely large, regardless of the species. Youll need a much larger tank if you actually plan on keeping the goldfish.

Despite what people say about them being easy, they arent. They are dirty fish that get big. Id say if you dont have a tank larger than 20 gallons, pass up the goldfish and get some other type of fish.

You could keep 2 fancy goldfish or 1 common/feeder goldfish in your 20 gallon, I don't understand the second part of your question.

If you need an algae eater get a snail, any more fish would not fit with the goldfish and it would lead to an excessive amount of ammonia and not enough water to dilute it, unless you plan on over-filtering just stick with the fish.

ONE fancy type maximum

or

NO comets/commons/feeders/long bodied goldfish maximum

if you want coldwater fish you could have 10 white cloud mountain minnows in your tank

Edit: eric_dss... that is not a good rule that is a terrible rule

Edit2: Dark Ryok those fish are only about 1/4 of there full grown size

Some people would say only 1 because of how big they get, but I think that's stupid. You probably won't even have the fish that long. So I would say you can have at least 10 small goldfish(1-2 inches) or 5 big goldfish(3-6 inches). The trick to healthy goldfish is to leave the tank dirty, so dirty that you can barely see the fish. I know it sounds untrue but it really is true, cleaning the tank often would just kill the fish. But you have to clean the tank eventually. But to help keep the tank clean get some snails. It would be so fun to watch them make a clean trail with their little mouthes. Some groups of goldfish that would be good together would be: group 1: comets,fantails and commons. group 2: black moors, bubble-eyes, telescopes, celestiels, lion heads and orandas. But this is my opinion of a tank, so it's actually your choice. Do what you feel is best. Hope this helped :D

I keep about 50 in a 10 gallon tank. Feeder fish tho

A good rule of thumb is 1 inch of fish per 1 gallon.

depends on their size

I would put 20 small ones in there once they start growing you have to cut down on their numbers..

edit...

Gold fish are not cleaning fish they are the dirtiest fish I know of.. you need pleco or some other cat fish variety to clean.