OK I'm stumped,heres my problem seen one of my fish rubbing the other night.well i checked every thing ammonia-0 nitrites-0 nitrates-20 heres the thing my Ph was 7.6 problem with that is my Ph out of the tap is 7.2.well what happened was i did a water change and it dropped to fast and st rest the fish right?my Ph has always been between 7.0 and 7.2 in the tank.so what i did is took a glass of tap water let it set over night Ph was between 7.4 and 7.6 this water is going from 7.2 to 7.4 7.6 over night what the !!!! is going on...