Ok so I need help. I have 2 tems about 5-6in long in a 420 setup. Currently one is laying upside down on the bottom of the tank rapidly breathing the other is right-side up also rapidly breathing. Tested my water and ammonia, nitrite, and nitrate levels 0 and pH is between a 7.6-7.8. Current tank temp is 83.9F. Did a 50% water on Wednesday due to med treatment for ick (used Mardel quICK cure). The usual w/c schedule is every 2 days 25-30%. Idk what's wrong with them but they aren't looking good and I have a lot invested in them. Any thoughts or suggestions.