Levels in 6+ mo. old tank. Ammonia .25ppm, Nitrate .25, PH down to 7.8, Nitrite .25. 80 gallon tank, 3 fish w/about 30+lbs of LR. Tank cycled months and months ago. All levels before water change were fine except Nitrate level which was about ..20 & .40.
All this has happened after doing...