Main Drain Necessary?

[ozz377]

I am looking to have a 45 year old pool renovated to include re-doing the lines. One company advised me that I don't really need a main drain. Anybody have an opinion on that? I have an 18 by 36 single roman with a depth of 3 in the shallow and 9 in the deep end...

[ps558]

I am looking to have a 45 year old pool renovated to include re-doing the lines. One company advised me that I don't really need a main drain. Anybody have an opinion on that? I have an 18 by 36 single roman with a depth of 3 in the shallow and 9 in the deep end...

With all stuff going on with anti entrapment nowadays get rid of it. They really are not needed and if the gov keep screwing with VGB laws it will cost you more to have a SVRS device added to the system, unless you have 2 drains a least 3 feet apart.

[Pool Clown]

If you have a pool cleaner, you wouldn't really miss the main drain. If you don't, you should get one (pool cleaner), or get used to vacuuming the pool yourself.

[Mark]

The APSP, has an interesting article regarding main drains and concludes that in most cases they don't really serve a purpose. A lower return is much better for circulation.

http://www.apsp.org/utility/showDocumentFile/?objectID=12

[chem geek]

That's an interesting article. The only thing I disagree with in it is the assertion that without a floor drain you can still have good circulation and they refer to above-ground pools and no reports of disease outbreaks. From numerous reports on pool forums, above ground pools with a single return not too far below the surface and a single skimmer often result in algae growth near the bottom of the pool where there is very little circulation in spite of FC/CYA ratios (measured a foot below the surface) that would normally prevent such algae growth.

Of course, a floor drain isn't necessarily needed to help improve the circulation and instead we usually recommend to point the return to the side and downward to try and promote a circular swirling circulation pattern, though just pointing downward to provide a rolling pattern would also be helpful (for the bottom circulation, though not necessarily for sides).

Having the return more strategically placed lower on the wall can help as can having multiple returns as noted in the article. So they are correct that a floor drain isn't needed, but their examples of above-ground pools isn't very good -- there may not be outbreaks reported, but clearly we've seen many cases of poor circulation as evidenced by algae growth.

[Mark]

Richard,

I think their main point was that the main drain doesn't really do much for circulation and at the bottom of the paper they have a link to a Youtube video which shows an experiment that they did. Anyway, they suggest turning the drain into a return which seems to do much better at circulation.

[Pathfinder]

This topic just came up in the new issue of pool & spa marketing a Canadian Industry mag.

Its an interesting read. Here is the online version its on page 32

No main Drain Article

[urpoolguru]

Switching the main drain into a return works better than just eliminating it. However if the issue is a broken line then just get rid of it. Ideally add a return or two low on the wall with a down jet eyeball normally used on in floor cleaning systems like a Paramount, Caretaker or similar system.

[GeorgeFrank]

The pool is redesigned to join line of burrowed around a 4ft profound opening and packed in solid shards to help give waste should I have to evacuate the attachment.