I have been battling low pH these last few days. Nights I there's a good breeze but day time no breeze and air is stagnet. I threw in a air line at. 440 this afternoon. Noticed in about a 2 hour period a great increase. I'm going to see where it's at by 9 pm. But I think it will be at or close to 8.0. the window in the room is open. But I don't think that's effecting to higher pH in the room since there is no breeze at all. Normally people say test 24 hrs but in a few short hours I think I'm good to replace the window and rig the airline through the window.