leak?

ethany

LifeTime Supporter
May 23, 2009
516
Trenton NJ
I have an inground fiberglass pool and I am losing water to where I need to replace water once every other day. I talked to a pool service person and he told me to mark the pool at water line and run the pump for 24 hrs and then do the same with pump off.

The thing that worries me is when I put the lever in just the main drain position I get a lot of air bubbles in the basket. When I put it in-between the skimmer and main drain most of the bubbles go away.

The frustrating thing is i put anti freeze in the lines last fall.

If there was a leak in the main drain, could it be plugged and the filtration system run normal? The man at the pool store said some pools are installed with out a main drain,is this right?
 

Melt In The Sun

TFP Expert
LifeTime Supporter
Oct 29, 2009
3,899
Tucson, AZ
Fix-a-leak won't work on suction plumbing at all (since it won't ever get pushed out the hole), and is not ever really a good solution for a pool leak. The main drain can be abandoned and the system run with just the skimmer, but that's not ideal.

Do the bubbles go away entirely when you only pull from the skimmer? Your main drain could be partially blocked with leaves, gunk, golf balls, etc, and that could cause the symptoms you're seeing.
 

ethany

LifeTime Supporter
May 23, 2009
516
Trenton NJ
Not entirely but there's a big difference. How could something get stuck in the main drain, i mean it has a plastic mesh cover on it in the deep end, I can't see how anything could get in.

If there were a blockage and i blew the line, does the cover come off?
 

Melt In The Sun

TFP Expert
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Oct 29, 2009
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Tucson, AZ
OK, here's what I was thinking:
The most common spots for air leaks are the pump basket lid and pump threaded inlet connections. With a leak in one of these two places, having lower suction resistance (your skimmer) means the leak will only pull a little bit of air. Turning the valve to the main drain makes the suction resistance (head) much higher, so the leak pulls lots more air.

It certainly sounds like you have a partial blockage in your main drain line. The drain cover probably attaches to the bottom of the pool with a couple of screws. You can try using a drain king (a balloon-like hose attachment available at most hardware stores) to blow backwards through the main drain line. You should be able to do this by opening up the top of the pump and putting the hose+drain king into the inlet hole, and turning your valve to the main drain.
 

ethany

LifeTime Supporter
May 23, 2009
516
Trenton NJ
How would this effect the loss of water? I did the bucket test overnight and this afternoon, about 10 min. ago I noticed about 3/8 to 1/2" of water loss in the pool and no loss of water in the bucket.
 

Melt In The Sun

TFP Expert
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Oct 29, 2009
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Tucson, AZ
Was the pump on or off during your bucket test? Were you pulling from the main drain or skimmer only? If you think the leak is in the main drain line, dive down there and plug it and see if your water loss stops.

Also, why don't you try relubing the pump basket and seeing if that stops the bubbles when running the skimmer only?
 

ethany

LifeTime Supporter
May 23, 2009
516
Trenton NJ
The pump was on and I was pulling from both the skimmer and main drain. Can I just switch over to skimmer only with the lever near the basket?

I will try to relube the pump basket. I did do that when I opened.

Since I have a fiberglass pool, the leak would have to be underground in the plumbing,correct? I do not have any signs of a leak above ground. What would cause this and do you think It would be warrantied? The pool was installed about 4-5 years ago.
 

Melt In The Sun

TFP Expert
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Oct 29, 2009
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Tucson, AZ
ethany said:
The pump was on and I was pulling from both the skimmer and main drain. Can I just switch over to skimmer only with the lever near the basket?
Probably.

Lets take a step back here first though to the simplest thing: have you checked to see if you're losing water out the waste line with the pump running? Sometimes if you have a bad spider gasket you can lose water to waste.

However, I agree that your drain line is a likely spot, since you have more bubbles when pulling from it. Try plugging the main drain line (that will require diving down, removing the cover, and plugging the pipe with a winterizing plug) and running another bucket test. If you still lose water when the drain is plugged, the leak is elsewhere and we'll try some more things.
 

ethany

LifeTime Supporter
May 23, 2009
516
Trenton NJ
Do I have to plug the main drain on the pool end, would it still leak if i do not pull water and i just switch the lever over?
 

Melt In The Sun

TFP Expert
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Oct 29, 2009
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Tucson, AZ
Yep, you need to plug it in the bottom of the pool to test it. Otherwise, if the leak is in your pipe down there, the water can still drain from the pool to the pipe and out into the ground.
 

ethany

LifeTime Supporter
May 23, 2009
516
Trenton NJ
What would cause this to happen? I know all the pipe is below 3' which is below the frost line.

What size plug would I need? The pipe coming out of the ground is 2"? I guess a 2" plug? Could I pick it up at home depot or do I need to go to pool store?
 

Melt In The Sun

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Oct 29, 2009
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Tucson, AZ
I think home depot would have it; we don't winterize down here in Arizona so I'm not actually sure :oops: Anyone else??

As for what could cause it; lots of things potentially, but I wouldn't stress about that until the leak is found. It may be somewhere else entirely.
 

ethany

LifeTime Supporter
May 23, 2009
516
Trenton NJ
Well I am not sure what this means but I ran the filter for 24 hours and lost about 1/4 - 3/8 of water. Same results with pump not running for 24 hrs.

So now what, does this mean its the main drain?

I have another question, there are to pipes in the bottom of the skimmer, I realize one goes back to the filter but what does the other do? Is it possible this pipe came apart underground?
 

Melt In The Sun

TFP Expert
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Oct 29, 2009
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Tucson, AZ
Generally, if it leaks the same amount with the pump on or off, it suggests that the leak is not in piping that is being used; i.e. in the pool shell or a currently bypassed pipe (like your drain is now). Just because there's another hole in your skimmer doesn't mean it goes anywhere, but you could plug it just to be sure. Have you tried plugging the drain yet?
 

ethany

LifeTime Supporter
May 23, 2009
516
Trenton NJ
This is what I did today. I put the compressor on the main drain, one of them blew bubbles like crazy and the other blew just a few. I kept the compressor on for about 5 min. to let pressure build up but the latter seems clogged.

Does this tell me its clogged or could the air not get through because its broken or came apart?

Tonight I am filling the pool up to mark I made on the pool and let the pool run bypassing the main drain.

One more question, is it possible to plug up just one of the main drain or do you have to do both? Oh by the way when I blew air I removed the cover on the drains.
 

Melt In The Sun

TFP Expert
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Oct 29, 2009
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Tucson, AZ
So, you have two skimmers, and the second pipe on one of them blows bubbles out the drains, but the other does not? If that's the case, your drains are plumbed through that skimmer, and the pipe in the other one probably doesn't go anywhere. If you want to isolate the main drain pipe, you need to plug BOTH drains, AND the hole in the skimmer that caused air to come out the drains when you hooked up the compressor.

How many suction lines do you have? Can you post a picture of your equipment? It sounds like turning the valve there may switch between skimmers rather than between skimmer(s) and drain.
 

ethany

LifeTime Supporter
May 23, 2009
516
Trenton NJ
Not two skimmers, two main drains. There are two pipes that come out of the ground one for the two main drains and one for the skimmer. When I blew the main drain pipe, bubbles came out of only one of the two main drains in the pool.
 

Melt In The Sun

TFP Expert
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Oct 29, 2009
3,899
Tucson, AZ
OK, got it; just misunderstood you.
That's strange. One is probably mostly blocked with gunk, but that may not have anything to do with your leak. If you want to test it for a leak you've gotta plug them. I really think that's gotta be your next course of action, and we can move on from that if you still lose water.
 

ethany

LifeTime Supporter
May 23, 2009
516
Trenton NJ
The frustrating thing is I am losing only about 1/4" per day. I read this is normal, but is it normal everyday to lose that amount of water? The pool is in full sun and it is an unusual hot summer this year.

I will go out this weekend and buy the plugs and give that a try. The only other place I could loose water is possibly around the return eyeballs. Since its a fiberglass pool, and doesn't have a liner that is not an issue.
 

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