Main drain Leaks...

[sgarofalo]

I posted in the another section of the forum before I saw this one. I apologize to the admins for re-posting but I couldn't figure out how to move my original post.

Hi everyone, going through our first closure of the season. Weather is getting pretty chilly here in Wisconsin and time to put the pool to bed for its long winters nap.

I had drained just below the return lines so I could blow those out, and all was well.

Didn't have time to finish that entire project and cover over last weekend and unfortunatley had some leaves fall in last week. didn't run the filter at all so ended up getting a little bit of alge growth.

Figured since I was able to empty the pool using the main drain and waste setting on the filter I could just run the filter using the main drain as the suction to cycle through a slam cycle and the cover it up for the winter. Worked well enough at first but what I am guessing happened is some leaves that were still left in there clogged the main suction line. When I scooped them out the water started flowing again.. This happened a couple times yesterday but I did end up getting the pool cleared of leaves.

Shut the whole thing down and when I looked out this morning I noticed the pool dropped about 3' of water over night!!!!! No filter running and the water was well below the skimmer and return lines when I ended so it has to be a main drain leak somewhere.

My question is, can I replace the "screen" plastic piece on the main drain with a solid cover and gasket and still be alright for normal filtering next year?

I do have a dolphin cleaner that could mix the water well enough I am hoping so there is nothing stagnant on the bottom.

OR would I have to hire someone to dig out, and potentially cut the side and bottom of the pool to find where the pvc blew out during my feable attempt at removing the alge?

 

[440dodge440]

I don't know the answer to your question, but is your main drain plumbed through your skimmer? The reason I ask is that despite the water being below the skimmer mouth, the main drain will still fill the skimmer box (it's pretty deep in the ground on my pool). I noticed when I was draining to waste, when I tuned the pump off it would still draw water unless I turned to multi port valve to a different setting to interrupt the flow....just a thought....

 

[sgarofalo]

Hi 44Dodge440,

The main drain is not plumbed through the skimmer. The current setup has three individual lines coming to the back of my garage, each with a shut off valve. One for each wall skimmer and one for the main drain.

I was able to close both skimmers when I was orginally draining the pool without any troubles.

My thought is to remove as much water as I can out of the main line, plug the main drain at the bottom of the pool either with a closure plate or some sort of expanding rubber plug or pvc fitting (if it is threaded). Fill as much of that intake line as I can with rv antifreeze and just leave it like that.

I've read a few other historical posts on new construction where people are actually opting to not have a main drain installed at all. With proper placement of return jets, and vigilance in water levels (not letting it get below skimmer lines to protect the pump from water starvation) I could get away with it without having to break concrete and dig below the pool.

 

[Catanzaro]

Shut the whole thing down and when I looked out this morning I noticed the pool dropped about 3' of water over night!!!!! No filter running and the water was well below the skimmer and return lines when I ended so it has to be a main drain leak somewhere.

I would rather not have a MD either. Are you positive that the water dropped 3' overnight? Did you have any leaks during the swimming season? A total of 3' of water will put you below the steel walls and down towards the vermiculite? This would be a serious leak. Can you determine if any part of the liner is showing water behind? Can you tell if you are still leaking water?

If the MD is in tact, chances are the leak is not from the MD. If the MD was constructed properly, this should not be an issue. Is there anyway the liner was damaged over the last few days? Hard to tell without a timeline and sequence of events, etc.

Determining where a leak is coming from could be solved by "Process of elimination". Allowing the water to drop until it stops would be an option. With this, there is always the risk of the liner developing wrinkles, etc. Other option is to call a professional, who specializes in "leak detection".

 

[sgarofalo]

Hey Catanzaro,

Pool held water all season and throughout the day yesterday too with no leaks.

I actually was watching the return flow throughout the day and it stayed an inch below all three return lines until I shut the pump off yesterday afternoon.

This morning (about 12 hours later) I did notice that I could see the bottom of the steps and it was completley empty on the shallow end and about 1 inch below the drop off to the deep end.

Quick look this morning did not show anything torn, or ballooned on the liner at all which made me think something blew on the main drain line throughout the night.

I'll double check again tonight when I get home to be sure.

 

[jrguzmanr]

From my experience the usual suspects when it comes to leaks are the skimmers and the lights. If you are below the skimmers and returns, it could be the light. As Catanzaro mentioned, letting the water drop until it stops is an option. if it were me and it continues to drop after the light, I would hire a professional. Specially since you lost 3 inches overnight.

 

[sgarofalo]

Thanks Jrguzmanr,

Water level is already below the light too, no other openings other than the main drain from here to the bottom of the pool.

It was closer to 3 Feet overnight though which is what concerns me. IF it continued at that rate the pool will be empty by the time I get home

 

[Catanzaro]

Water level is already below the light too

I would monitor at this point. If the leak stops, then you know it is at the light. Track the amount of water loss per hour, day, etc. (if you can) so at least you have an idea how fast you are losing water below the light. At this point, you are left with a few possible areas for the problem. This could be at the MD as you suspected all along or at the stitching below the steel walls, and/or a possible tear in the liner. At the rate of water loss, you would be nearly empty within 2 days.

 

[sgarofalo]

Thanks for the reply Catanzaro,

I'm not to confident it is a tear in the liner. It was replaced last summer prior to us purchasing the house. Water level was below the light and all return intake lines prior to the loss of water. No one has been in the pool since I initially drained it except for our dolphin vacuum.

I'll check again tonight but in my mind the only thing that could have happened is the main drain pipe either collapsed, or blew a fitting at some point when I was circulating the water and the leaves clogged the drain to the point where no water was getting to the pump.

Didn't notice any water loss until this morning when I looked outside.

BUMMER!!!!

So if it does completely drain, and I can get either a threaded plug or rubber expansion plug in the main drain line, how tough is it to refill?

Liner should still be fairly elastic being less than a year old. Is it safe to walk on the dry liner to the deep end to plug the drain?

 

[OldPoolMan]

Its ok to plug the main drain, the pol and a cleaner would make up for any suction issues. Anyway, the average pool in the US does not really have any suction from the main drain I would think that your main drain would have a 1 1/2 or 2" threaded suction hole. I threaded plug would work for that.

 

[Catanzaro]

Sgarofalo:

Here is the situation. If the water completely drains out, I would call the Liner Company. Because liners have elasticity, it could have taken a year before any installation errors became visible, i.e., you losing water. I have a friend who claims that sometimes liners become damaged and weak, only too see a problem a year later. If this was me, I would allow the water to drain down and call the Liner company. They can come back and inspect everything to figure out where the problem is (At this point, it should be very apparent). You could have an issue with the light niche, the fiberglass steps, etc. It could very well be the MD. The plumbing probably did not come apart at the MD. Closing the MD is the not the solution (unless it really is a pipe that burst underground).

Where exactly is the water line right now? Can you take a picture and upload? How much water have you lost from this morning?

This morning (about 12 hours later) I did notice that I could see the bottom of the steps and it was completley empty on the shallow end and about 1 inch below the drop off to the deep end.

I am trying to get a feel of how water you are losing at this point, and how many hours have passed.

 

[sgarofalo]

I'll take a pic tonight when I get home.

I should have taken one this morning but I do know exactly where the water line was when I left this morning.

Water was below the light niche for a week prior to me messing with it yesterday.

Only thing that did change was me running the filter using the main drain only and it getting clogged twice which prompted me to cycle the filter after clearing the leaves from it. I was thinking the suction from running the pump dry then priming a few times could have pulled the pvc apart. The leak is definitely below any and all openings other than the main drain.

I like you thinking though and will see if the warranty on the liner extends to us being the new owners of the home/pool.

 

[Catanzaro]

I am trying to get a feel of how water you are losing at this point, and how many hours have passed.

Can you please give us an idea on water loss? Where exactly is the water now? Are you still losing water below the light?


The warranty should be also on the installation, not necessarily the liner. I would get the liner company there to determine if the leak is caused by the installation. This would be easy as the leak could be where the company cut the liner, either around the light niche or the MD.

 

[Catanzaro]

Good Morning:

Any updates? Is the water level still dropping? Thanks!

 

[sgarofalo]

Hey Catanzaro, Sorry for no replies yesterday it was pretty bad with the water loss so I called into work and did some repairs.

Couldn't get a pic on Monday night after I got home as it was to dark and they didn't turn out.

Next morning it had about 10 inches of water in it and appeared to be holding at that level.

I was able to get in, and remove the cover off of the main drain anticipating using one of my 1 1/2 inch threaded plugs to close it off but it was not threaded. Grabbed a marine grade rubber and brass expansion plug from menards and put that in and started to fill the pool. So far it is holding water and is now filled to the point where the drop off meets the shallow end.

Here is a pic of what I was working with.

Original line showed the "Maintained water line" for the week prior to this fiasco. Didn't check the pool at all until next morning and the second line shows where it was at when I posted my original questions. After work it was to dark but I put in white letters where the water was at and final line shows where it appeard to be leveling off prior to me plugging the main drain line.



- - - Updated - - -

Not looking forward to that water bill when it comes in

- - - Updated - - -

Spent the day watching it fill and doing some outside stuff, constantly using my pool brush to help smooth out any wrinkles as the pool filled. So far when I checked this morning it did lay pretty flat and I didn't see any wrinkles in the liner at this point.

 

[Catanzaro]

I was able to get in, and remove the cover off of the main drain anticipating using one of my 1 1/2 inch threaded plugs to close it off but it was not threaded. Grabbed a marine grade rubber and brass expansion plug from menards and put that in and started to fill the pool. So far it is holding water and is now filled to the point where the drop off meets the shallow end.

We have to back up a little. In your picture, you stated that "Water Level held here overnight". If the water held, why did you plug the main drain and fill up? I must be missing something. Your MD is at the other end with a slope in the base of the pool. If the water held, it appears that the MD is not the issue. If indeed your MD, all the water would have been pretty much gone.

Did you check the liner for any damage? A leak of this nature would be easy to spot. Please advise!

 

[sgarofalo]

I did get in the pool and walk the entire bottom of the floor looking at the entire liner. No tears or rips of any kind.

Sorry the pic did not show the main drain at all but yes it is right in the middle of the pool on the flat portion of the deep end.

My thought was that while that drain plugged with leaves the suction of the pump may have pulled a fitting or collapsed it some how. For me to lose that much water that quickly it would have to be a pretty large tear in the liner and go through the concrete base I am guessing. Well guessing it is concrete, the pool was built prior to me purchasing the house.

We live near lake michigan about 1 mile away and have three or four smaller 3 to 4 acre ponds that are within two houses of us. All well below the grade of our pool, and when I was putting the fence in this summer the soil was extremely sandy. I'm guessing that the water flowed directly into the ponds as we had no seepage into our basement nor did any of my neighbors. 20,000 gallons of water gone in less than 12 hours I would have thought someoone would have had a flooded basement or at least some sign of water. Sump pumps never kicked on either.

 

[Catanzaro]

Steve:

Did the water level hold overnight above the MD? If so, could it be something else? I would stop filling the pool up and wait 24 hours to determine if you are again losing water? If not, then it was the MD.

My thought was that while that drain plugged with leaves the suction of the pump may have pulled a fitting or collapsed it some how. For me to lose that much water that quickly it would have to be a pretty large tear in the liner and go through the concrete base I am guessing. Well guessing it is concrete, the pool was built prior to me purchasing the house.

I do not believe this is the case. The plumbing is all glued together and chances are that it would have not come apart. It is possible that something shifted in the soil causing a break in the plumbing. If this happens, you would see large divots in the vermiculite/concrete base and the liner would show this around the MD area. This is why I am still wondering if the MD is really the issue.

 

[sgarofalo]

Thanks Catanzaro, all very good points. I will have my wife shut off the water today at lunch and take a pic of where the water line is at that time then double check when I get home and through tomorrow. At the point where it is now, its not to far off from where it would be normally for the winter closure so I shouldn't be to concerned with any other damage from an empty pool.

When I was in there there inspecting the liner I didn't see any divots anywhere around the bottom or sides, main drain was firmly attached when I was plugging it too. entire bottom felt solid across the whole thing.

Getting close to snow falling here in Wisconsin so I really really hope we don't have to do any major excavation prior to snowfall!

 

[sgarofalo]

My wife was able to shut off the water at lunch and snap a pic of the current level. I'll double check tonight when I get home.

Maybe I am paranoid or just plain bored at work but I was looking into different types of main drains just now and ran across something like this hayward main drain.



Which is Very similar to the one I have.

There is a 1 1/2" pipe coming into the side which is what I assumed was going back to the pump and filter. then another assembly on the bottom of the housing that was about the same diameter as the hole in the side but had what looked like some kind of something in it..

After doing some reading online, I'm thinking it is one of those hydrostatic relief valves that is installed to prevent ground water from pressurizing to much from under the pool.

Could that relief valve be forced up, or open due to the filter trying to suck the water through the grate which could or would have caused all the water in the pool to flow out of that valve? Never really saw one up close to see how it is supposed to work, but after all of this, if that is the case that would royally stink!!!

#5,6 in the pic shows a threaded plug but mine is in the same position but actually came up from the bottom of the housing about 2 inches.