[Chrispy]

well since the fish are already in there what your problem is is the bacteria. your tank is cycling now with the fish in it. so....... wow. read up on cycling your fish tank, i assume your going to to a fish cycle. i dont know the link of the top of my head, but someone will post it. there is a long thread here about cycling. keep up the water changes as always. if you happen to have any old fish tank stuff that you can throw in it would help or if anyone you know has a fish tank up and running that you could steel the filter from and plop it in your tank. 3 weeks means your in the middle or near the later part of cycling.