I stopped using the Alkaline + Acid combination due to the constant PH shift. I now use only the alkaline to get it to a KH of 2. It works better for me since my tap is KH = 0 and GH = 6 PH = 5.5. I age for 12 to 24 HRs. also 7.5 is not that bad PH better a 7.5 stable than jumping around.