the title says it all.... in my 20 gallon i had a common plec, blue gourami, 5 redtail tinfoil barbs (small), and a baby angelfish. In a desperate attempt to get rid of the grim on the walls and junk floating around everywhere ( i sorta saw that comin with all these fish), i did wat seemed to be a 90% water change. Bad move, killed my angelfish and 3 barbs. The gourami and the plec are survivors...they've been through alot. Anyways, plz dont flame me as i knew the tank was overcrowed from the start, im just really depressed right now. r.i.p fish.