One skimmer and one return line for entire pool


Active member
Aug 6, 2018
Hi all,

I have a 15x30 inground vinyl pool. The pool is over 40 years old and has black polyethylene piping. Currently, there is 1 return line (there used to be 2, but 1 was closed by the previous owners), 1 skimmer, and 1 main drain. We have a leak in our return line and I believe another leak in the main drain. We're losing 2" of water a day. I called a leak detection company and the first time they came out, they said our leak was a cap near our pump. There was a small drip coming from it, but I knew there was no way it was causing 2" a day. He claimed that it could be worse when we aren't looking. Either way, I got it fixed. As expected we were still losing 2". They came out a second time and found the leak in the return line (where we originally told them the leak was). Fortunately, it's in a very easily accessible location. We're getting it repaired Monday.

However, I'm still noticing a loss of water, even with the return line plugged. I did a bucket test today and lost 3/16" in the bucket, but 9/16" in the pool. I had done the test previously with similar results, so they checked the main drain gasket, skimmer faceplate, and liner for leaks but found nothing. I asked them to come out a third time and they are planning to pressure test the main drain. My understanding is that the black poly piping is the old way of doing things and they are notorious for leaking. If the leak is in the main drain piping, we will most likely have to close it permanently.

This would leave us with one skimmer line and one return line for the entire pool. Any reason to be overly concerned about this? I was told that this is okay for our size of pool, but haven't had the best of luck trusting some of the contractors. The good news is that the skimmer line and return line are both short and easily accessible.


Bama Rambler

Mod Squad
TFP Expert
Bronze Supporter
LifeTime Supporter
Jun 22, 2009
SouthWest Alabama
With that size pool you should be fine with one skimmer and return. A lot of pools that size have only one skimmer and return. Unless you're reworking the entire pool, it's probably not cost effective to try and replace the line to the MD (Main Drain).


TFP Expert
Mar 2, 2011
What pump do you have?

You should limit the pressure and flow to reduce the stress on the plumbing. The lower, the better.


Gold Supporter
May 16, 2010
Chapel Hill, NC
If you have access to the sides of the pool anywhere, then installing another return would be advisable if you need to close off and seal the main drain.


TFP Expert
Bronze Supporter
In The Industry
Aug 10, 2017
Morris Cnty NJ
it would be great if you could get the other line repaired if thats possible, but 1 skimmer and a return will work for that size pool. as said keep the pressure down, you could add a bypass if needed if the current pump is huge. you dont really need a main drain but a second point of suction is always good to keep from running dry