Main drain/No Main drain

HarryMichael

LifeTime Supporter
Apr 26, 2007
101
Baton Rouge, La.
Hello... This is my first post..Hello to All, :D PB said he does not install Main drains in fiberglass pools any longer. He said water is pumped from skimmer to cartridge filter back to pool.
Also he said I'll only need 2 returns on the size pool I'm getting which is 15x34, 8700gal.

My two questions are: 2 returns, do I really need more and do I really need a drain on the bottom of pool??
Thanks...Harry
 

CarlD

Well-known member
Apr 8, 2007
104
HarryMichael said:
Hello... This is my first post..Hello to All, :D PB said he does not install Main drains in fiberglass pools any longer. He said water is pumped from skimmer to cartridge filter back to pool.
Also he said I'll only need 2 returns on the size pool I'm getting which is 15x34, 8700gal.

My two questions are: 2 returns, do I really need more and do I really need a drain on the bottom of pool??
Thanks...Harry
No and no. I have 16x40 20,000 gallons with one return, a skimmer and a low drain on the side wall and I'm fine. No main drain. No problem
 

SeanB

TFP Expert
Platinum Supporter
LifeTime Supporter
I don't know the facts behind this debate, but this article is certainly compelling.

From Pool and Spa News:

Dual drain debate continues - letters
Pool & Spa News, July 12, 2002 I just finished reading your article on the Florida main drain code (6/7/02 issue).

I have been designing swimming pools for about 40 years. My standard procedure of the design of wading pools was to connect the main drain to the skimmer.

About 15 or 20 years ago, at a swim club in the King of Prussia, Pa. area, at a wading pool of my design, a 4-year-old boy sat on the main drain whose cover had been removed. The skimmer was clogged. Seventy-five percent of this boy's intestine was sucked out through his rectum.

Although I was absolved of any responsibility, the picture has never left my memory and subsequently, I have never designed any pool of any size without the use of at least two main drains sufficiently separated to preclude this ever happening again.

Regardless of the final code wording, the pool builders, for their own protection, should insist on the use of two drains.

Mitchel Abramowitz, AIA
Lansdale, Pa.
 

HarryMichael

LifeTime Supporter
Apr 26, 2007
101
Baton Rouge, La.
I don't want to debate dual drain for that is what I asked for when he said he does not put drains in anymore. I just want to make the right decision. Can I live without a drain in the pool....also two returns, is that OK?
Thanks!!! Harry
 

sevver

Well-known member
Mar 27, 2007
477
Morris, IL
Honestly, I would say that two returns should be fine, all they do is return. You just have to keep water moving around in a circle I think. As for no MainDrain, I can see definately not wanting to put one under a fiberglass pool for sure, you would have to have everything dead on when you set it, and it could potentially be several settings in and out of the hole. I think that personally I would want a main Drain just for the fact that you would have the option of circulating water during a partial drain, like if you had to repair something. And I suppose, if you are doing one, may as well do two. But if you were to get a skimmer problem, and had to drain it for a few days while it was fixed, with a drain, you could keep the water from going that lovely green color.
I see it as an insurance policy I guess.

Steve
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,624
SW Indiana
The dangers of main drains have been pretty well eliminated by the introduction of new covers that prevent entrapment. That said, there are many good arguments that the drain isn't needed for good circulation. They are often a source of leaks, and things are expensive to fix when the drain leaks.

Two returns ought to be okay unless you have alcove type steps or a tanning ledge. You'll want a return in there to keep debris from accumulating.
 

peterl1365

LifeTime Supporter
Mar 28, 2007
242
Murrieta, CA
I would suggest that if you have any significantly concave areas in your pool that you insist on a return specifically in that area. I have 3 returns, but there is one area that has very poor circulation and floaters just congregate in that section.
 

TheOne

LifeTime Supporter
Mar 28, 2007
167
Houston, TX
This must be unique to fiberglass pools because I couldnt imagine not having a main drain. I sweep dust/dirt/leaves to my main drain regularly. I also have flagstone coping which causes more initial dust than most probably. I can switch my suction valve to pull exclusively from the main drain and set the pump to high speed and brush away. During normal pump run time I set my suction valve to about 60% skimmer suction and 40 % from the main drain. In an 8700 gal if you have some type of vac system it probably wouldnt be that big of deal to not have one though.

Also 2 returns seems fine for 8700 gal. The shape and design of your pool should also help determine the number of returns. I have 4 pool returns but 3 of the returns are positioned to "sweep" benches, steps, etc.
 

kenlorz

Active member
May 1, 2007
26
Choconut,PA
I choose Not to go with main drains at the last minute. The store owner actually talked me out of it. NOT for saftey reasons but for depth. I'm almost 6' tall..if I jump in feet first and hit one I'd probably bust it! Can you say $$$$$$!!!!! Main drains are safe enough now, I belive most states now reqiure that two mains be installed on the same line and they must be several feet away from each other to prevent entrapment. I think you'll be just fine on that size pool without them...IMHO. :wink: