Hey I have two parrot fish. Around 8 years old. I recently did a water change two days ago and added the conditioner and salt as usual. I have a whisper 20 and a aquaclear 116 filters and a filter fiber air filter in I think 60 gallon tank approx. Checking the water the pH was fine the ammonia level was at zero and the nitrates between 20 and 40 ppm. The female got sick right after and I thought that maybe it was her time since she was old until 2 days later when I found her on her side and the male now laying at the bottom of the tank. I set up a smaller tank put them in there because I have no idea what is wrong.