Hello, so my tank has plenty of flow and water breakage at the top for ample oxygen/co2 exchange to happen. What I was curious about is, if my house runs fairly high co2 levels, avg between 900/1000 (which is an issue with my older hvac system id assume, without opening windows it stays high) does that high co2 level in home, cause less exchange of oxygen back into my tank due to the higher levels in my home? or does it automatically pull and exchange what it is releasing from tank and pulling the right amount of oxygen? Is the Sera oxygen test that says it's for freshwater work in my saltwater? Didnt know if readings would be correct.