Customer's pool has poor circulation. I think her pump motor is undersized.


In The Industry
Jul 3, 2013
So, my customer has about a 35000 gallon 20x40 inground with 10-12 total returns. Last year she replaced her liner and they also replaced the pump motor. The filter is a Hayward s244t sand filter, the pump is a Hayward Super Pump, and the replacement motor is 1hp. The pool has 2 skimmers and no main drain. The pool has a set of stairs with 2 returns, a swimout with about 6 returns, and 3 pool returns. Recently I fixed an air leak at her pump union. I thought it might help her circulation and it did, but it didn't cure her problem. I had to shut the valves for the swimout just to get a decent flow from the stairs and pool returns. IMO, even with the swimout returns closed, the flow is too low. 1hp just seems grossly undersized to me. Am I wrong? If I'm right, what size motor does she need? I thought a minimum of 2hp would be what she needs.


Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
Sebring, Florida
I'll bet you are right. 10 returns sounds like the problem......not enough flow to keep the pressure at an acceptable level.

You could experiment by putting smaller eyeballs in the returns if that's possible. What is the working psi?

A larger pump (especially a VS) seems right but the eyeball changeout is cheap.


Well-known member
Jun 16, 2019
I have a 20X40 with 35k gallons. I have 2 returns in the shallow end pointed at the 2 skimmers in the deep end. My pump is a 3 HP with 2.5 inch plumbing. I have turbulent flow for days. So much so i never had to pull my 16 mil solar cover back on the pool. All i had to do was turn the pump on high and unroll at the reel.


TFP Expert
Mar 2, 2011
As long as the skimmers work, why do you care about the returns?

What are the trying to achieve?

What do you think better flow will do for you?


TFP Expert
Mar 2, 2011
Usually, to use a feature, you close the other lines.

If the feature doesn't work to the customer's satisfaction, then you probably need a bigger pump.

If you want to use multiple features at the same time, you probably need a bigger pump.

The correct pump would be a 2.7 + hp variable speed pump.

A single speed pump would be a bad choice.

You want to run slow until the customer wants to activate a feature and then only enough speed to get the feature to work correctly.

You should have a bigger filter to handle the flow rate.

Automation would also be helpful so that the customer can push a button and activate the feature.
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