I believe I only have one option here (well 2, but option 2 is more expensive), and I am testing those waters out today. I ran my skimmer intake line outside in the hopes that more fresh air will keep my pH up at night. Since summer (we don't have spring in North Florida) rolled around (and those dreaded 90s moved in), our apartment has remained closed up. During the winter, the door to the apartment was open for large stretches of the weekend and evening, allowing the exchange of CO2 laden air for O2 laden air from outside. As such, my pH seldom dropped below 8.0. However, now my pH has been dropping as low as 7.67 at night, which is dangerously low. Due to the low end dropping so low, the high end only reaches 8.10 now. I need to get the low end pH up obviously, which will fix my high end (which isn't low by any standard) as well. I'm hoping that the outside air corrects this issue as I do not want to invest in pricey CO2 media. Other things to note: Yes I have cross tested with to pH meters Yes I have calibrated the pH meters No I'm not running a calcium reactor Not really sure why I posted this, as I already know the suggestions lol.