So i finally got to checking the ph in my water barrel(which holds roughly 80+ gallons). All I have in it is a heater and lots of aeration. However I have a bit of a problem the ph in my water barrel reads 8.2 my small tank water and the water coming out of the tap reads 7.8 my bigger tank reads 8.2 Ive been wondering what is causing the ph in my water barrel to spike. I can't seem to find out what is causing this, so I thought maybe it was the water barrel its self. I switched over to a 50 gallon hex glass tank, filled it up stuck a heater in it with lots of aeration and then checked the ph, it reads 7.8; I woke up in the morning checked the ph again it reads 8.2. So I was wondering, can too much aeration cause a swing in ph?