Octo 150SSS airline?

[pjdiddy]

My PH is low, 8 max and 7.6 minimum, I'm thinking of fixing it by running an airline from my skimmer to the outside. I currently use an Octo150SSS and I have no single idea how and where the airline goes. Tried google and didnt find anything. Thanks in advance and happy reefing.

 

[James M]

That’s a good Ph level

 

[pjdiddy]

That’s a good Ph level

Is this a regular fluctuation tho?