Raising and stabilizing PH
 

My PH is the only parameter that I have not been able to adequately control. It drifts between 7.8 and 8.1 or slightly lower. I tried many things, at same time and independently. The big three were 1) airing out the fish room with fresh air (I live in a new house that is tightly sealed), 2) dosing kalkswasser in my ATO, and 3) using a CO2 scrubber with CO2 adsorption media attached to the air inlet on my skimmer. Have to say, after a few weeks of isolating variables it is 3) CO2 scrubbing that did the trick. My PH is no stable in the 8.2 to 8.35 range.

That makes sense. Most houses run a bit high in carbon dioxide, which lowers the pH. I'm glad the scrubber was able to help. Sometimes aeration via the room air overwhelms the scrubber, from what I can tell from people's reports.

For your reference, i'm running a sodalime CO2 scubber, a reverse cycle iluminated small macro algae reactor and a Ca reactor. The daily swing of pH is about 8.05~8.25 just after the sodalime is replaced. I replace the sodalime when the lower end reaches 7.80.
While 5~7 visitors stay in my living room where the tank is located together with my 3 family members, it drops 0.15~0.20 within 2~4 hours during winter time due to the elevated CO2 in the room.
This is a bit better than those of the local reefers living in apartments.
The measurements are made by hanna hi 8424 regularly calibrated.

Thanks for the information!