So today has been confirmed that something is going on with my 20g tank. I am trying to figure out the source that is causing my pH swing and other water levels. Here are my results from today: pH - 6.6 nitrites - 0 ppm nitrates - 0 ppm ammonia - 0 ppm temp: 81 F The last time I performed a water change was on 06/03. And my results from that day (before the water change) are below: pH - 7.2 nitrites - 0 ppm nitrates - 0 ~ 5 ppm ammonia - 0 ~ 0.25 ppm temp: 78 F I haven't done any water changes in between my readings (aside from that one I mentioned). I also haven't added any chemicals or replaced my filter/ cartridge whatsoever. I have also been feeding my fish once a day (definitely not overfeeding). However, one of my grapevine driftwood is going through a fungus phase (it's been this way for over a week now). Any help I can get in trying to figure out why the changes in my levels would be appreciated. Thanks.