How much difference in PH. is there in a planted tank with aeration vesus no aeration? Using 7.1 tap water! My tap water is 7.1 but the tank stays above 7.6 The tank has a sump, and this causes fine air bubbles. I also have 2 large pieces of driftwood in there, and I thought they would be somewhat acidic. The bottom is pea gravel, Neutral ph I hope!