I'm VERY new to this whole fish thing, but I have a 30 gal.(US) tank that I set up about a week ago, and there is a horrible smell coming from it. Of course it's a fish tank, and it's going to smell, but this is worse then my friends 30 gal., and my 10 gal., any suggestions on how to tame this? Is there an excessive amount of waste that can cause this? I have a silver cat shark, an albino clawed frog, two skirted tetras, and 2 angels. Is there an anti-smell fish I can buy?