I've had this 65 gallon aquarium for over a year and haven't been able to keep any fish alive for more than 2weeks except for my striped Raphael Catfish and mystery snail. Water temp is at 79, pH is 7.7, nitrates around 20, nitrites 0, KH 40, GH 60 and ammonia between 0 and 0.25. I have one...