Vinyl Liner Main Drain in the wall

itst_9

New member
Feb 10, 2020
4
Albuquerque, NM
We have a 9'18' Intex Ultraframe pool going on its 3rd summer. Last summer I changed out the factory inlets to 1/1/2" making it standard pipe. No leaks occurred and this worked great. However.

In tinkering with things I am wanting to change the drain plug (see attached photo of plug location) from the factory 3/4" Intex fitting to 1/1/2" wall fitting. Searching and reading I do not see where anyone has upgraded the small drain plug in a vinyl lined above ground pool. It looks common to add a main drain on the floor of a vinyl pool but not on the wall. Is this because of the static pressure on a 1/1/2" fitting at the bottom of a wall would not hold up and be a prone weak point to leaking?

I was going to use a fitting like the "wall drain" image attached and cut out the 3/4" existing drain. Then plumb this new fitting straight to the pump. I was also thinking of adding a large patch over the existing area to make the pool liner a tiny bit thicker and silicone all parts before I put them together. This pool is seasonal so it goes up in April and down in October.
 

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JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
16,241
Tucson, AZ
If you are going to add a drain that size, then you need to comply with the Virgina-Graeme Baker Act regulations to avoid suction entrapment. Drain covers must be VGBA compliant and you must have two drains separated by at least 36" on the same suction line. You don't see wall drains and large drains on soft side pools because the risk of suction entrapment and accidental drowning would be higher and thus have greater liability for the manufacturer.

Remember, when you modify your pool in any way, you void all warranties and assume ALL liabilities and risks. If your modification led to someone getting hurt, you'd be on the hook for all legal damages. I'm not trying to scare you off, just want to make sure that the point is made. A larger drain is a great idea in principal from the standpoint of hydraulics, but there are downside risks to adding larger drains.
 
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itst_9

New member
Feb 10, 2020
4
Albuquerque, NM
Thank you all! I appreciate the good info and pointing out the VGBA requirement. I can not believe I have not read/heard about that and will be passing that info on.

Just how rigid is vinyl? Am I likely to see much stretching under the weight of the water with a larger hole at the bottom of the pool? If a lower drain is installed is a threaded drain vs a drain that has screws better to use? To me I think either type would be fine but am still learning. Searching the forum it seems like stretching does occur.

If the vinyl is likely to stretch Im going to re-think a different plan.

A sump pump is used when we break the pool down in the fall. The thought on this drain addition was for better pool filtering being able to pull water from the bottom of the pool without having to use a robot or extend the current suction intakes (VGBA approved) down into the water.
 
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jimmythegreek

TFP Expert
Bronze Supporter
In The Industry
Aug 10, 2017
1,708
Morris Cnty NJ
Many pools have wall drains especially fiberglass pools. If you want to mix water well point the returns downward. Sucking water from deep doeant do as much as you would think. Water movement is the key. If you were to add wall drains you plumb them 36" apart and T'd into the same line but I haven't ever seen an above ground with this setup before. I would add returns and just point them down before I would add wall drains. They are called deep returns usually set lower by a foot max
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
16,241
Tucson, AZ
The placement of the skimmers should take into account prevailing wind patterns. If the wind blows stuff away from the skimmers then they will be ineffective most of the time. Also, make sure deep end ladder placement accounts for location of skimmers and returns. I don’t know how many times we’ve seen PB install ladders right in front of or too near to skimmers and returns making them ineffective.

I, personally would add another return on the short wall in the deep end and/or would inquire about adding separate deep returns to help with heating. It’s very easy for shallow wall returns and skimmers to create a thin layer of heated water on top but leave a large volume of colder water in the deep end well. Water mixes and homogenizes a lot less than you think.

Will there be no main drain in the pool ? Lots of debate on the pros & cons surrounding that
 

itst_9

New member
Feb 10, 2020
4
Albuquerque, NM
Much appreciated. I never thought wind patterns would take a toll on cleaning but it makes sense. Ladder placement will be noted as well.

As of right now no main drain. I have considered the idea of adding one but that means saw cutting my backyard patio.

Im getting excited for a great pool season this year.
 

cfherrman

TFP Guide
May 10, 2017
2,436
Hays, Kansas
I would only go with a wall drain to aid in heating, it will do Jack for anything else and just possibly add problems, this also kills yours skimmers you need to run around 90% skimmer suction, and you can't just shut off the drains as you need to keep water through them to keep them clean, so you need to tune the system very precisely.

If I would do this use the double suction Intex fittings ~6" off the bottom.