2in pipe with 1.5in connections to equipment


Sep 22, 2019
Chattanooga, TN
I have an above ground pool that had the pump and filter installed right next to the pool. About 7ft of pipe to go from skimmer to return with the pump and filter in the middle. While it's disconnected for winter I'm moving the pump and filter a little further from the pool into a small shed (well ventilated) for aesthetics purposes. This will increase the pipe distance to about 25ft total and add 2 90 degree elbows (there are 3 existing 90s). The skimmer and return are both 1.5 in. The pump basket has a 1.5 in input and the filter has a 1.5 in output. However, from the pump basket to the pump is 2 in and from the pump to the filter is 2 in. The pump is 2 speed 1.5 HP.

To summarize: [skimmer] 1.5" <---> 1.5 " [pump basket] 2" <---> 2" [pump] 2" <---> 2" [filter] 1.5" <---> 1.5" [return]. All the piping I would be extending/replacing is in red and would be using 1.5" connections to equipment.

I see a lot of data on why 2 in pipe is better than 1.5 in, especially when 90 degree elbows are concerned. But does it make much difference if all the endpoints are still 1.5 in? If I used 2 in pipe would those 1.5 in connections create any problems? Am I thinking about this too much? With only 25 ft of pipe and 5 total 90 degree elbows it's a relatively small system.


Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
Bedford, TX
Howard, Christopher

You will not be able to tell any operational difference between 1.5", 2" or a mix of plumbing , on a standard residential pool. There may be some theoretical difference, but not enough to notice in actual operation.


Jim R.
Last edited:


Well-known member
Mar 13, 2018
DesMoines / Iowa
I ran 2 inch mine was 1.5. At the pump its still 1.5 but you can tell the pump doesnt have to work as hard to pull water from the pool. On mine anyway. the only line that is 1.5 now is for the pool cleaner. if I open just that, the pump works harder then if i just open the 2 inch skimmer or if i just open the bottom drain. the cost from 1.5 to 2 is not that much I would run 2 :)


LifeTime Supporter
May 2, 2011
Long Grove, IL
For the difference is cost between 1.5 and 2" I would go ahead and use 2" but don't expect anything to substantially change with regard to flow, electricity usage, noise level, etc.

larger cannot hurt you here.