Main Drain Leak

Dec 1, 2010
3
Hello everyone. This seems like a great site.

I have a leak in my main drain. I noticed the leak when I turned off the pump last month, so I knew it was somewhere on the suction side. I've let it go for about a month to where it drop too and it's now below the pool light and returns. My pool guy says it should be ok to plug the main drain and just run off the skimmer. Looking around the net, I can't find a definitve answer to this. I should say that I have no way of turning off the main drain. I only have one pipe coming out of the ground so I know the main drain and skimmer lines join up. I was going to just drain the pool and plug it, but i'm fearful about my pool cracking or popping up. I"m in Austin, TX. If that makes a difference. I've also seen a product called Fix-A Leak who some people have had success with. I was planning on running a pipe to the main drain and pouring some in and seeing if it would work. I'm sorry it this is somewhat incoherent, but I'm totally confused about this. I guess the easy response is to suck it up and call a professional, but I'm trying to cut my costs if at all possible.

It's an inground pool. Guanite. 11 feet on the deep end.
 
I'd just plug it (if you are positive that is where the leak is). As long as you keep the water elevation up high enough for the skimmer to draw properly there really is no need for the main drain.

Is this an old pool? Do you have a dedicated suction line for a pool cleaner also?
 
you don't need to drain in in order to plug the bottom drain. there are adapter plates than can be swapped out in place of the plate that is on the bottom right now. anyone can hold their breath for a few minutes and if you can't, give a swimmer kid couple bucks and a screwdriver. turn off pump first.
 
Since your MD and skimmer are tied together you'll need to plug both ends of the MD line or water will flow backward into the MD line.

The most common way of tying them together is in the bottom of the skimmer. Check to see if your skimmer has two pipes in the bottom of it. If so, one of them is the MD connection. You'll need to plug it. You may have a diverter in the bottom of the skimmer, and you'll have to remove it to access the MD line.
 
Since water temp in Austin is getting a bit cold for diving, unless you like that color blue in your skin... you can also hire a service company who does underwater repairs with dive suits who can plug the main drain with the pool full, and should also make sure the main drain is sealed at both ends. As Bama mentions, the two holes in the bottom of the skimmer, one should be the MD line. The hole closest to the pool interior is usually MD and the rearmost hole usually goes to the pump. Best to verify this before permanent repair. With the pump running, one of the two holes will have great suction, the other will feel idle. The one that feels idle is the one connected to the MD.
 
Thanks all of you for the info. I had no clue about the main drain being connected to the skimmer. I've been reading through this site for the past couple of days and I wish I'd stumbled across it a long time ago. It would have saved me a bunch of headaches.

Yeah, the water is too cold for diving, that's why I was hoping to just drain it and take advantage and wash the plaster. Most people have told me it should be fine to drain it, but it makes me nervous either way.
 
If you need to plug the MD and don't care for the other options presented, you could probably drain the pool, plug the drain, clean the plaster and then refill the pool. You won't want to leave it drained for any significant length of time and don't do it during wet weather. The biggest danger is from water pressure building up underneath the pool & floating it, which would be a major repair. Hydrostatic valves aren't always dependable because they can get clogged with gunite/plaster/debris & may not respond properly. Ground movement can also cause the pool shell to shift. Pools get drained on a regular basis, but you might want to consult a professional in your area who can advise you on draining procedures for your area.
 
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