Running the media dry is pretty much a waste. I got just about 10 days out of it.
Running with water in the reactor and pulling normal ambient air lasted just over 30 days.
Running out of the skimmer cup and the media has lasted just about 50 days, so a significant improvement in longevity and without looking at the logs I'm pretty sure the average pH has also increased over time.
Not planning on productizing this and can share some of the specs and code as well as some 3D designs for the enclosures. I can change some things so its Arduino friendly for the average hobbiest.
That's cool for those of us that like to tinker (better messing with the gadgets than the tank, lol).
I need to connect mine to my skimmer so I can get anywhere near 50 days. I get 7-10 days.