how long

how long should I wait to get fish for a new tank

Thats a pretty good question. What you should do is buy a really hardy, CHEAP fish. The reason being is because you want to start the cycle of the aquarium. The cycle is explained in depth in some other decussions, but what it basically is, is the benefical bacteria that turns fish waste and food into useable plant food.

So to come back to the fish, the reason that you want to get a couple fish, is so that cycle starts sooner, and the rise of ammonia is completely elimanted when you introduce new fish.

So once you buy a few fish, I would wait at least a week to introduce fish that your tank can handle. If you wanted to be safe, you could wait 2 weeks. The bigger the tank the more time you should wait. A 10 gallon is about a week, a 50 gallon I would say 2 weeks.