Not getting much of a pH raise from CO2 scrubbers?

[Treldeham]

I have two Bulk Reef Supply CO2 scrubbers hooked up in series to a Coralife 220G skimmer in a recirculating setup in my 180G FOWLR. Without them before the pH tended to be around 7.7 and I would use Seachem's Marine Buffer to raise it to the 8.2 range. I set up the CO2 scrubbers about two weeks ago, but my pH has only gone up to about 7.9. Is there something wrong I've done with my recirculating setup? I know my skimmer isn't the best, but I have a low bioload tank and it has done well enough. I can't take in air from the outside because of the positioning of my tank unfortunately. I have tried leaving a door open during the day (the tank is in the basement so no windows) to raise pH as well, but that didn't have an effect.

 

[Tim617]

I would suggest an industrial strength pump and airstone and not using a skimmer.

 

[Waggers]

This looks interesting

 

[Tamberav]

I would not even raise an eyebrow unless it started dropping below 7.8 consistently.