Since I moved to Lake Havasu City, Az the PH in my 300 gallon system has been running lower than I am used to. For a big portion of the year it is too hot to open the house up. I do run a calcium reactor but leaving it off for 24 hours did not make a difference in the PH neither did turning off the skimmer for 24 hours. I put an air stone in a cup of water in the same room as the tank and PH did not change. If I poke a hole through the wall behind the tank it goes into the garage, so I tried the air stone in a cup of tank water in the garage and the PH went down even lower. When I did it outside in the open air in two hours it went to 8.26 so I figure the tank is at equilibrium with the co2 levels in the house. I read in Randy's article and others that a PH around 8.0 should be fine. Alk is 8.6 dkh, calcium is 450, magnesium is around 1350. My question is would it be worth the work to run the skimmer airlines outside? I know it would help to bring up the PH but it still would not bring it up to the same as open air to the outside as the co2 within the house would still be getting into the tank water. I could run the airlines for the skimmer pumps temporarily through a window to see how much difference it makes but how much time will it take on a 300 gallon system with a large skimmer for it to reach the maximum increase I will see?