PVC Pipe Size

[Markymarks]

Hey folks. Happy pool opening season!

So have had some kind of suction side leak for the last 3 years and decided that instead of trying to find and fix it in the flexible spa tubing to just go to hard PVC piping.

What size do you guys recommend for a 18’ above ground with just under 8000 gallons 1.5” or 2”? Looks like the skimmer and pump both have 2” threads on them. Currently the skimmer goes down to 1.25” then opens to 1.5”.

Thinking of doing the suction side 2” and eventually when I do the rest hard PVC it will be 1.5”.

 

[needsajet]

It depends a bit on pump HP, but yes, compared to the effort of doing it, the cost of 2" vs. 1.5" isn't much. On a short pipe run, you may not notice any difference.

Just in case... check those threads you mention. Those might be meant for unions rather than pipe thread. Most pool plumbing is done with glued slip fittings, and then unions are used to attach to fixtures. Unions have their own thread size, non-tapered, and rely on an o-ring to seal. You can buy a fitting with 2" pipe thread (that can be returned) and just test to find out. It should turn easily until around two or three threads are covered, and then start to grip as it goes on further.

Nice to meet you via TFP and happy pool season to you as well

 

[Markymarks]

Tried the 1.5” unions I have and they are bigger than the male threads on the filter, pump and skimmer.

Looks like I need a 2” threaded fitting to see if that fits.

Wondering if the whirlpooling I get when the skimmer basket is taken out has to do with the piping going to 1 1/4”.