I discovered that the red platys and black lyretail mollies in my new aquarium have ich. The fish were perfectly healthy until I added a school of neon tetras, then a few days later I noticed white spots on the platys and the mollies. The neons seemed healthy, but I think they had a few spots too. I bought the medication, and it said to add one drop for every gallon, and half that amount for tetras. I didnt know how much to put in because I wanted to make sure the livebearers were properly treated but I didnt want to harm the neons. I lost two platys to ich, and I must have put too much medicine in because 4 of the neons have lost their colour and then died. I dont know what to do!! Should i stop treating the fish (the medication bottle said to treat for three days but I read u should treat for 12-14 days to ensure all the parasites are killed) How many drops should I put in? How can I save my fish?!