I have been battling low Ph all winter. I bought an apex for my new setup, so of course I put it on this tank for the time being. The Ph was 7.7 when I hooked it up, and fell to 7.5 that night. I opened the windows in the room and it has brought it up some. The low side is getting just below 7.8, and getting up to 8.1 during the day. I also have a kalk reactor sitting here for the new tank, but its hard to have a float switch with the wp25 in there. Today I have had it! Ph was under 8 at 3pm. So I mixed a gallon of kalk, got out some tubing and a gang valve and started dripping. I have it dialed in for 1 drop every 10 seconds. Hopefully this will help with the Ph being so low.