I am not sure what is going on with this tank. I have had it set up since October last year. There are three apple snails in the tank and no other fish. The snails have been in the tank since it first cycled about the middle of October. The tank had been cycled but then something happened and the cycle died. PH had tanked and ammonia spiked. I did a complete water change on the 27th of March. I changed out the rock and put down a thin layer of aragonite and top fin aquarium sand on top of it. The ammonia levels have been constantly at 1.0ppm. I have been doing daily water changes and dosing with both Prime and Stability. Today when I tested the water my readings were at PH = 8, Ammonia = 2.0, Nitrites = 1ppm, and Nitrates = 20ppm. I did a 50% water change and dosed it again with Prime and Stability. Is this tank starting to cycle again?