heres the situation...i noticed a while ago one of my cichlids that is bright yellow, started getting these blacks spots on the end of his tail. then his lips started to turn black. so the other day i treated for ick and other parasites with some stuff from pet smart, after i did a 30% change. then 2 days later, one of my spotted catfish was dead. now another day later, my other spotted catfish is dead. also i noticed my tetras top fins arent really standing up like they were...they kinda drooping down. also noticed the fish dont seam to be as lively. any suggestions?? im far from a fish expert. and have absolutely no idea what to do. i might start with another water change tonight after work. maybe like 50% or something. but please i need some help. i really dont want to lost all my fish!