Skimmers & Returns: What's the Right Number?

[TKpoolOH]

All, I thought this might be the best forum to post this question. I'm in planning stages over the next year or so to build an inground vinyl liner pool. How does one determine the appropriate number of skimmers and returns for their pool? I ask because it seems all the suggestions on the construction forum indicate many more skimmers and returns that I would have expected.

My first home I owned had a 20x40 inground vinyl pool approximately 30K gallons with an 8 or 9 foot deep hopper. This pool only had one skimmer and as I recall just one return (it may have had two and I can only remember the one). I never had any water quality issues and never had any issues cleaning it either. Just ran the barracuda suction side cleaner once a week for several hours. I was doing liquid chlorine so once a week I would add some and every two or three weeks I'd have the pool store test it while I was buying supplies.

Am I missing something on the number of skimmers and returns needed?

 

[mas985]

As you found out, almost any pool could get away with 1 each but it helps to have a few more returns to improve skimming and circulation and for that size pool, I would have at least 4 returns. For skimmers, it is more about placement and wind direction. If wind is primarily from one direction, really only one skimmer is necessary no matter how big the pool. But it can help to have a second skimmer if wind alternates directions or the pool has an odd shape where debris can get trapped in two locations. More than 2 skimmers in most cases is probably not necessary. Skimmer placement is about where the debris is likely to end up. Having a skimmer up wind is not going to do much for you.

 

[thetekgeek]

My pool is irregular shaped, 17 X 33 free form. I have 2 skimmers placed opposite each other, typically the wind blows in one of 2 directions here so they are placed strategic to that. I have 5 returns. I use the eyeballs on the returns to push surface debris towards each skimmer. I rarely have leaves make it to the bottom of the pool because everything that hits the water gets caught either in the small current created by the returns or the breeze pushing it towards either skimmer. I would recommend at least 2 skimmers and however many returns your builder is willing to put in before the cost starts to go up.

 

[TKpoolOH]

Thank you for the responses. The explanations are very helpful.

 

[mas985]

There are disadvantages to too many skimmers and returns especially if energy consumption is an important factor. The more skimmers you have the higher flow rates will be needed to run them effectively. Two skimmers require twice the minimum flow rate of a single skimmer and if you have a VS pump that will require 2x the RPM which results in almost 6-7x the energy use. With a single speed pump it doesn't matter much since the flow rate is more than enough to support multiple skimmers. With returns, the effect is less important but too many again means the flow rate is divided up between the returns so with many returns, the flow rate out of a single return can be much less effective at pushing debris toward a skimmer. Placement of returns is probably more important than the total number (e.g. opposite skimmers, near steps, etc).