All I can say is since I added the CO2 scrubber amd did the recirculating method my ph jumped up. (Obviously not from recirculating) but doing this I’m going on week 3 with media and no color change at all. I did plumb an outside line hooked up to a valve to open up if ph gets to high to allow fresh air in and pinpoint my ph. Overall I am happy. I did notice my skimmate is less now though probably has something to do with recirculating. Here’s a graph pre amd post scrubber. I went from struggling to get 8 during day and 7.7 night plus ph was all over at times to 8.2 day to 8.0 night consistent.