Whats the best goldfish tank size? What aquarium is big enough. You should also get a descent quality filter.
Theres more to the goldfish tank size question, like what can happen if the tank is too small, can you put different goldfish species together in one tank, and how do you keep their tank water clean?
What size tank do goldfish need then? At least 120cm x 50cm x 50cm should be the very minimum for fancy varieties, while commons/singletails should not be housed in anything less than 200cm x 60cm x 60cm.

This particular example perfectly highlights why Goldfish Tank Size For Soft Water is so captivating.
Goldfish Tank Size Formula. A simple starting estimate for fancy goldfish is to give the first fish a base amount of water, then add extra volume for each additional fish. The calculator uses this rule-of-thumb
Discover the ideal tank size for your Thai Oranda goldfish and learn how to care for jumbo Orandas in style!

If you have two common goldfish, a tank of 50-60 is the ideal size. Try to aim for a tank with more water surface area than depth, because goldfish prefer longer tanks. For two fancy goldfish, however, a 30-gallon tank can work.
Tank Size For Fancy Goldfish. Fancy goldfish require less space.Goldfish Tank Size Calculator. Here are formulas that will be helpful for you. The way to calculate it depends on which shape of your tank is.