Co2 into Skimmer

[cccharliecc]

I have a Reef Octopus 3000int skimmer and it has two air intakes on it.
If I want to run a tube to outside my window or wall in the house for fresh air intake, this should raise my pH correct?

Also my biggest question is do I need to run the air tube from outside to both the air intakes on the skimmer or just one?

 

[EmdeReef]

Yes, running an air tube outside should help raise ph.

Not familiar with that skimmer.
the one below?

https://www.bulkreefsupply.com/super-reef-octopus-sro-3000int-8-in-sump-protein-skimmer.html

Maybe I’m not seeing what you are referring to but if you are talking about the skimmer silencer...then keep the cap on one as shown in that pic, and run the tube in the open one.

 

[cccharliecc]

Yes, that is the exact scammer I have.
Mine has both open, no caps on mine

 

[EmdeReef]

The cap is there to keep the skimmer quieter unless you’re running ozone or something that may require using both. You can just duct tape it if you don’t have the cap that came with it.