I need help! I have a 125 gallon freshwater tank, which has been extremely healthy for the fish. Recently I added plants, with 384 watt light, CO2 injection, timers, and so on. Added plants. I had a major algae growth, which was cured with Algae Fix for planted tanks. Plants did not look well, excessive algae growth again, and a high nitrate level. I did 3 partial water changes with in a week adding SeaChem's Neutral Regulator. Nitrate level down to 20. Greenish cloudy water returned. Added two doses of Algae Fix within a week. Water still cloudy. Added two doses of cloudy water clarifier. Water still cloudy. Right now I am in completing a 4 day blackout, with CO2 off. But now this week my fish are dying. Monday I lost 6 fish in one day and so far have lost 12 or more fish this week. Both fish and plants are dying. I have a pH of 7.0, 0 ammonia, 0 nitrite, and still about 20 nitrate. What is wrong? What can I do? I am planning on another partial water change today, but what else?