I set up my fish tank exactly one week ago. Last saterday i added water to the tank, dechlorinated it with stress coat and let the filter run. The next night i added two sunburst platys and three neon tetras. I believe the neon tetras were sick before i bought them, but I didn't realize. They got Ich and i treated them with API's "Super Ick Cure". They didn't make it, but because of the medicine i had the ammonia carb out of the tank for 4-5 days. i put it in again yesterday, and tested the PH and ammonia levels today. The ammonia was about .5 and the pH was high too. I bought pH down and put that in the tank today. How often should I add pH down to the tank? When should i check the pH again? I know ammonia levels can be a little high while there are no new fish in the tank, but i would like to adjust my water to be perfect so that i can add some new fish. I don't have a heater, the tank is about 70 degrees, room temperature. The platys seem happy, but i would like to take all precautions, any advice?