No drains - do you need additional skimmer

[Vesper]

Hello,

This is my first post and my first question - lots of info on the forum

We are installing 18x36 in-ground pool (20000 gal, 613 sq. feet) with Hayward EcoStar Variable Speed Pump.
The pool will have no main drains as stated by the PB.

Here are my questions, based on the above specs:
1. How many skimmers should there be? Is more needed since no drains?
2. How many returns should there be?
3. 1'5'' or 2' pipes?

Thanks!

 

[Nectarologist]

A pool that size I'd want 2 skimmers with a main drain so maybe tell them 3 to circulate more water? It still won't circulate the deep water well though. That being said I have serviced pools with one skimmer and no main drain and they seemed ok (basically really old concrete pits). I assume a main isn't possible for some reason right (not that the PB just doesn't want to do it)?

My pool is a bit smaller (16x32) and I have 5 returns coming off 3 main return lines. The feed that goes to the stairs splits to 2 returns and the feed that goes to my bench splits to 2 with another independent run to the wall. I have no issues. Can't help on the pipe size, sorry.

 

[pooldv]

Welcome to TFP and congrats on the new pool!

1 skimmer in the right place is enough, 2 is better. Make sure they are downwind in fall #1 and spring #2 to work best. 3-4 returns is good. 1-1/2 pipe is good, 2 is better.

 

[mas985]

Main drains are not necessary to keep a pool clean and well sanitized. APSP, has done a study on MDs and came to this conclusion some time ago:

http://www.poolinspections.com/manuals/drains/pools-without-drains.pdf

Since MDs don't really add much to the circulation and sanitation of a standard pool, the skimmer placement and return placement should not be any different than a pool with MDs.

2 skimmers may or may not be better than 1. It depends on which way the wind blows. I have 2 skimmers but I could easily get away with only one as most of the debris ends up at the skimmer in the deep end.

Also, with 1 skimmer and a VS or two speed pump, you can usually run at lower RPM than if you have two skimmers since you are splitting the flow rate between the two skimmers. So if you can get away with one skimmer, it can actually save in energy costs.

Also, since I use a pool cover most of the time, the skimmers are pretty useless until I remove the cover.

For returns, I would have at least 4 and all 2" pipe. For suction side, I would go with 2.5" pipe for a single skimmer or 2" pipe from skimmer to pad if two skimmers.

Returns are far more important for distributing chlorinated water back to all parts of the pool so just make sure they are equally spaced around the pool.