Skimmer tubing to outside air question?

[HighChiefKC]

Ok, so I’ve struggled with low pH, and I’ve read to run tubing from the skimmer to outside air. 2 questions, where do I connect this tubing on my skimmer? And what size/type of tubing do I need?
I have a R.O. Regal 250 INT as pictured below. I’m assuming it either goes where the black rubber cap is, or the open hole right next to it? Thanks!

 

[Philly Reefer]

The open hole next to the black cap. Keep the black cap on.
Cause what we want is the skimmer to draw outside air in.
I use a regular airline tubing. As long it fit almost thigh in there, you should be fine

 

[HighChiefKC]

1/2” or 1/4”?

 

[Philly Reefer]

1/2” or 1/4”?

Not sure what mine is actually.
But this is what I use

 

[DeniableArc]

Hi I have done this with great results. I would bypass the cup with the black cap on it and measure the diameter of the inlet directly on the skimmer pump and buy the biggest tubing you can for that outside diameter. The reason for this is you want the biggest tube with the least resistance especially if you plan on running that line a long distance. The tube I used has a outside diameter of 12 mm and inside of 10 mm which I believe will fit straight on a brs co2 scrubber inlets. I tried using a scrubber with outside air and I feel it was a waste and the ph ended up very high

 

[HighChiefKC]

Hi I have done this with great results. I would bypass the cup with the black cap on it and measure the diameter of the inlet directly on the skimmer pump and buy the biggest tubing you can for that outside diameter. The reason for this is you want the biggest tube with the least resistance especially if you plan on running that line a long distance. The tube I used has a outside diameter of 12 mm and inside of 10 mm which I believe will fit straight on a brs co2 scrubber inlets. I tried using a scrubber with outside air and I feel it was a waste and the ph ended up very high

Thanks for the tip because it’s going to have to go about 20 feet or more