So I have been using store bought RO water and soaking it for 3 days with sphagnum peat moss. When I test it the ph level is about 6.6. After a couple of days in the tanks the ph will jump back up to 7.6 and I can't seem to figure out why or what is making it jump back up. I have sand for substrate, some malaysian dw and sphagnum peat moss scattered throughout the tank. Does anyone know why my ph would jump back up?