Main Drain - help me understand my pool and my issues

[Gary Young]

Ok - I don’t understand my plumbing in a pool i didn’t design and I wasn’t here when it was built.

I need to understand it better.

Its a bent L shape, with two skimmers. It has a main drain and there are five outlets.

A couple problems:

I can never get the bottom of the deep clean.

If I open the valve for the main drain, it inevitably kills my prime.

I drained the pool so I could deal with the Bottom and there was about two inches of mud and the drain was fully clogged.

I cleared it all and pulled the drain cover and unclogged it all. I noticed that there are two holes in the main drain, one from a pvc line that sits at a right angle from the drain collection area itself.

There is a second hole that is in the bottom of the collection area, but it has a plug in it.

Can someone explain to me what I am seeing, whether I ought to pull that plug out, and why i can’t hold prime with the drain valve all the way open.

Idiot alert - I dont know very much at all about what I am dealing with.

I am very appreciative of TFP and consult the board often. I can’t find another thread on this or I would not bother anyone —

Gary Young
Lincoln, Nebraska
30000 gal in ground
Hayward Aqua Rite SWG
Starite Sys 3 37sq ft DE filter
Hayward SuperPump 10ft lift
vinyl liner
and lots of trees

 

[sktn77a]

If I open the valve for the main drain, it inevitably kills my prime.

Well, this would suggest a leak in the plumbing somewhere between the main drain and the pump.

 

[Arizonarob]

Yeah as Keith has said, it sounds like a leak. Gary can you snap some pics of your equipment pad, and if possible the main drain plug you are referring too. Thanks.

 

[Jimrahbe]

Gary,

Welcome to TFP.. a great place to find all the answers to all of your "Draining" questions, no matter how old your are....

A picture of your equipment pad showing all the valves and pipes coming into your main pool pump would really help us provide you with better answers.

I am not sure what is causing your problem, but thousands of pools don't have operating main drains and they all work just fine.

Are you even sure that the main drain is plumbed back to the equipment pad?

An operating main drain will not keep the deep end "clean"..

Do you have a dedicated vacuum line in the side wall of your pool? If not what type of pool cleaner are you using?

Thanks,

Jim R.

 

[Divin Dave]

Hi Gary,
Main drains are a non essential pool element. They really are not needed. The dont do much for cleaning anything and little for circulation.

Anyways, I'll throw in my .02, for whatever it's worth.
the two pipes. One of them goes to either your equipment pad, OR - it goes back to the skimmer. Look into your skimmer and see if there are two pipes in the bottom. If there are, one of them goes to the MD and the other to the pump.
.
the other pipe in the MD Ts off and goes back to the 1st one. If you have a MD, its supposed to comply baker graeme act. Its a safety thing.
Virginia Graeme Baker Pool and Spa Safety Act - Wikipedia

If I were to guess at it, someone plugged one of the ports to try and get more suction in the other port of the MD.

If it were my pool, I would just completely plug the MD and be done with it and not worry about it anymore. Its not worth the time, effort or worry of it leaking...etc.