Brian, I did some testing prior to deciding on the Scrubber. I stabilized my dosing until I had three days of less than 3 points swing in ppm on the Hanna alk checker. I then left the windows open for 3 days. Immediately the next day alk consumption knocked down the ppm by 8 ppm. So I started dosing an additional 5 mL. I then closed the house up like normal and the pH dropped. The ppm on the alk went up 9 points. Signaling less consumption. At this point I have left the dosing regimen the same and I will test again when I get home. I am expecting to see the alk back to where it was when I had the windows open. I know this is far from scientific, but it is good enough for me. For what it's worth, I didn't notice a change in Calc, but I manually test that with the Red Sea kit.