Want to pipe skimmer to draw in outside air- What size pipe?
 

I'm guessing the reason behind the chronically low ph in my tanks is because they are in the basement. I want to run pipe so the skimmers use outside air. I cannot find a table, or any information, on how to choose the right size pipe. Seems all tables/calculators I've come across deal with pressurized air.
It'll be about a 30 foot run to each skimmer. I'd like to size it so 300+/- scfh could be handled.
Anyone know where I could find a sizing table/calculator? Or does anyone know what size pipe I would need?
Thanks

um all you would need would be a long surgical hose ran from the venturi of the skimmer to outside. There is no pipe needed

also the max scfh is determined by the body diameter of the skimmer and neck size of the skimmer and of course the pump.

I'm no engineer, but I'm pretty sure you couldn't suck even 50scfh through 30 ft. of surgical tubing. There is this thing called friction...

Right. Thanks

There is no skimmer i am aware of either that can handle 300scfh. It would have to have a huge neck ( probably in the 16-24" range)

A 30 foot length of airline tubing would restrict air without question and lower the total volume of air the skimmer was drawing so I understand what the OP is asking. What you said is like saying "the mouth and lungs are what determine the airflow in and out of a human, but not accounting for the stirring stick straw as an intake *LOL*

I was just designing this part of my system. The pump / skimmer I will be using will draw around 90 scfh in which I will probably go with 1" pvc. I am just worried about the location of the air draw as I BBQ on the back porch and do not want smoke ingested or any chemical spray from an exterminator *LOL* Still thinking this over.

lol. Can you imagine how big the body of the skimmer would be?!
Actually, the pipe will be to vent at least two skimmers- an ATI BM250, and a SRO 5000 cone. The ATI pulls in the 70's, the SRO in the 80's. Maybe another skimmer down the line.
I'm planning on running pvc along the floor joists, and there will be at least 2 or 3 90 degree turns in each line. The tanks are not near each other. I figure if I size the pipe for double of what I actually need, I'll be safe if I upgrade or add another down the road.
That being said, I really don't want a 2" pipe sticking out of the wall if it's not needed.

One thing we have here in Mo. that you are missing in Az. are cold winters. I'm hoping with a 30' run the air will have a chance to (somewhat) warm a little before it gets to the skimmer. I'm more concerned with when cold fronts move through in the winter. The winds sometimes really howl, and I worry if it might actually force air into the skimmer.
Opinion?

I would not worry about forced induction at all and I am not sure what the cold air effect would have temp wise on the tank. We have the opposite here in Az, would be sucking 115 degree temps *LOL*

I supply outside air to my Reef Octo 200 using a length of approx 15 ft of 5/8" vinyl tubing. I got a 20 ft roll from Home Depot for like 10 bucks or so...I was careful to avoid kinking or twisting it when I set it up. My tubing actually runs from the skimmer pump to behind the tank, through a 3/4" hole in the floor, along the basement foundation wall, to an outside air vent. I made a little "cap" out of some window screening for the open end, so I don't have to worry about bugs getting inside the tubing.

Anyway, I was able to easily breathe in plenty of air through the vinyl tubing; certainly more air than the skimmer could pull.

P.S. - I wouldn"t worry about the winter air affecting your tanks temperature or "forcing" air into your skimmer... that won't happen. And colder air tends to have a higher O2 content than warm air, so that should be a good thing.