I had 2 silvertips in a 30gal w/ 2 irridescents, recently one silvertip just randomly showed signs of stress i guess and then died a day later...done know why or how, i ahd them both bought them together at the same time about 3 months ago and they used to both swim around the tank together all the time, after this one died my other one seems to be depressed...either that or is about to die like the other one. Water levels and chemicals are normal, temp is normal, and both irredescents are fine. Why did the first silvertip die, and what should i do about the last one i have. I know he's a community fish so should i get him another silvertip to swim w/? He basically just sits at the bottom of the tank in the corner where one of my airhoses comes into the tank, kinda like a shelter over him, and then eats, swims around the tank once or twice in a few hours, and then goes back to the corner for the remaining time. Whats going on, anything else i should check for or do? Thanks for any info.