Hello,
The tank is fifteen gallons, water change fifty percent every two week, nitrate ppm 0-20, nitrite ppm 0-.5, alka. Ppm 80, ph, 7.2-7.8. He has 2 male guppies 3 male mollies, had 2 phantom tetra lost one and lost one pleco. The latter 3 fish are new to the tank were added about 1 1/2...