I have killed a lot of fish with copper and chloroquine phosphate. Maybe those new fish were not showing any symptoms, but still were too sick to survive. However, the fact is that I always used PROPER dosages, yet a significant percentage either stopped eating or just died. So I have decided to keep a fully cycled 150 using Turbostart and ammonium chloride to keep it going, and whenever I get a new fish, just put it in that tank and only medicate it if I see obvious symptoms of disease. So far it has worked. I took some foxfaces, moorish idols and a good sized angel out of copper, where some were dying and some not eating, most doing well, and put them in a clean saltwater tank, no meds. It has been three weeks now and everybody looks and acts great. So my question is this: Does there EVER come a point where I can be confident that they are ich and velvet free so I can feel safe putting them in the display tank? 350 gal, medium density population. Thanks in advance.