Hi, I checked my levels for my water for 1 week continuously. Ammo, Nitrite, Phos, PH and Salinity, all mention are at 0, PH 8.0, Temp: 82 to 80f,and 1.024....maintains at that level for past 7 days. But my Nitrate are at constantly 20ppm....water change 20% it'll drop to 5ppm but 2 days later...