I bought some neon tetras and guppies a week ago. The neons were quite tine and I wondered if they would make it, but I still have 5 of the 12. Guppies are all gone...had bought 3. Now ,y zebra danioes that I have had for a month with no probs are starting to die. I can not see anything physically wrong. My water parameters are good, and I did extra Wc when this started. I am going tomorrow to buy a quarantine tank, which I know I should have bought before. Did a 50 percent WC today, is there something I should add to the water to help the fish who have been already exposed to this...besides prime of course?