Idea for testing leaks at bottom of pool

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W

weird_tolkienish_f

0
May 31, 2013
148
Massachusetts
My pool has the dreaded slow leak, I failed a bucket test this weekend, however there was rain, so performing one right now. It has already partially failed.

I have checked all the suspects. Skimmer, returns, some cracks, light opening. I want to check my main drain bottom.

My idea was to take aquarium tubing, put a check valve at the end of it, put food coloring in it, tie it to a pole using duct tape, submerge it to the main drain opening and blow.

Otherwise I just cannot find this leak. There are no bubbles in the pump bask whatsoever, it's complete water, with nothing more than condensation forming around it. The area around the pump is bone dry. This leak has existed for a few years now. It's so slow that I usually live with it, but now it's a real nuisance.

I will be retesting the area around the light but my initial test showed nothing. I have never gotten any dye to flow into any of the plumbing that I can check.
 
CNJ_EC said:
weird ...

First & foremost ... I hope your pool lights are on a GFI breaker that's tested monthly!

Regarding the leak ... Have you inspected the Hydrostatic plug(s) on you MD's? When were they last replaced?
Click to expand...

I tested the GFI break on the pool light last month. Breaker trips. When untripped light works great.

I Have never inspected the hydrostatic plug on the MD and have no idea when it was replaced. I do not use the main drain but it is "open".
 
Weird .... not sure what you mean when you say that you don't use the MD but it is open. Open as in the MD grill is exposed or do you mean something else?

You're main drain is part of the pool circulation system. The plumbing configuration of the MD is going to be one of the following:

Separate suction line back to the pump
Piped directly to one of your skimmer's - in which case it might have a adjustable valve in the skimmer;
Piped via a tee fitting or equalizer on the skimmer's suction line.

How many of suction lines are tied into the pump?

If you are sure everything else is ok and the MD is the problem then I would start with the Hydrostatic Plug - they don't last for every and when they fail your pool is at risk.

If you do the dye test ... best thing is to get a decent mask & weight belt this way you can see things close-up. If it's a slight leak - your not going to see it being on the deck.
 
CNJ_EC said:
Weird .... not sure what you mean when you say that you don't use the MD but it is open. Open as in the MD grill is exposed or do you mean something else?

You're main drain is part of the pool circulation system. The plumbing configuration of the MD is going to be one of the following:

Separate suction line back to the pump
Piped directly to one of your skimmer's - in which case it might have a adjustable valve in the skimmer;
Piped via a tee fitting or equalizer on the skimmer's suction line.

How many of suction lines are tied into the pump?

If you are sure everything else is ok and the MD is the problem then I would start with the Hydrostatic Plug - they don't last for every and when they fail your pool is at risk.

If you do the dye test ... best thing is to get a decent mask & weight belt this way you can see things close-up. If it's a slight leak - your not going to see it being on the deck.
Click to expand...

Thanks for your reply, CNJ. THe MD is a pipe that is connected to the skimmer basket only, without a diverter valve there is no suction at it whatsoever. I do not use this valve usually.

My house is at the top of a hill and I have never had any dug hole ever fill with water. My basement has never had a drop of "naturally" occuring water in it, just washing machine line water, etc. (yeah yuck, I know). I do not believe my water table is high and that my pool would pop, of course, I would never want to chance it either.

Using food coloring was what I was trying and according to what I read on the the internet it is basically useless. I will be buying a syringe of pool leak detector dye. The leak is extremely slow, I would guess on the order of 1/2" to 3/4" per day. The water level lowered but the pool did not empty over winter, I also had holes in my pool cover from mice, and I was draining from top of the cover a lot, this was responsible for some of the lowering. But the fact that the pool did not empty makes me think maybe it's not the main drain.

The skimmer is heavily bonded and shifted and prior to this week I strongly suspected this was the source of the leak. Now I am not so sure. I neglected my pool for an entire week and the level dropped below the skimmer basket. I also have no bubbles in my pump basket whatsoever.
 
"I neglected my pool for an entire week and the level dropped below the skimmer basket."

Did the pool stop loosing water when it dropped below skimmer? I think if you let it leak down until iy completely stops you should be able to find what is leaking, that is IF it stops leaking.
 
Non-technical explanation: In the Skimmer ....you'll never have suction from "B" ... all of the suction is from "A". You can use any food coloring tube demo this.

Follow rp's suggestion .... you need to rule out the skimmer being the problem. Can you drop the water level just below the skimmer? If you have a secondary pump like a Little Giant or other brand submersible pump it wouldn't take that long to drop the water level. Then you could watch it for 24hrs and decide what to do next.
 

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CNJ that is exactly what I have. I have no gotten any food coloring to suck into anything, without the pump being on. What I have heard though in searching on these forums is that food coloring is completely ineffective and will just disappear with any movement of the water, something I can concur. I ordered some actually pool leak dye, hope to find the leak. May also let the pool get draining until it stops. Pool dye should arrive in 2 days. Can't wait to solve this long nagging issue and I hope I can solve it at all.
 
Weird,

In relation to the skimmer ... how far down are the return jets? Have you sealed them off and do they hold pressure with out leaking?

When you have the dye kit ... In order to test the MD correctly, you'll have to remove the cover/grill ... while you're down there ... test the Hydorstatic Plug. If you hlave an underwater camera ... be sure to get a couple of good shots of the Hydostatic Plug. The pictures will help ID the plug and it's extraction/installation tool. Some come off really easy .... others can be a real PIA.
 
Weird ...

Nothing wrong with using a tube or two of food coloring for a quick suction test at the skimmer or MD.

Open the Skimmer
Remove the basket
Squeeze a couple of RED drops into the skimmer
Watch it get sucked into the suction line
Distance to the pump and the pump's RMP will determine how quickly the water in the pump's strainer basket turns RED. Water in the pump's strainer basket will clear in about 30 seconds.

Repeat the same process for the MD
MD sucks it in
Water in the Skimmer turns RED
The rest is the same as above

Not very scientific but a good cost effective visual for the customer.
 
CNJ_EC said:
Weird ...

Nothing wrong with using a tube or two of food coloring for a quick suction test at the skimmer or MD.

Open the Skimmer
Remove the basket
Squeeze a couple of RED drops into the skimmer
Watch it get sucked into the suction line
Distance to the pump and the pump's RMP will determine how quickly the water in the pump's strainer basket turns RED. Water in the pump's strainer basket will clear in about 30 seconds.

Repeat the same process for the MD
MD sucks it in
Water in the Skimmer turns RED
The rest is the same as above

Not very scientific but a good cost effective visual for the customer.
Click to expand...

I bought a snorkle kit online, should be arriving in a few days. The bottom main drain has leaves in it to be honest. I have tested it previously and never gotten suction (by pushing leaves towards it) without installing this diverter valve that the previous homeowner left. When the snorkle arrives I will try to get the leaves out and test the main drain for leaks and suction.

I put as much food coloring in the skimmer basket (and skimmer opening) as possible while pump was off, it stayed stagnant. I then turned the pump on, the water quickly evacuated. I did see the water in the pump basket turn red. There is literally not a single bubble in the clear pump basket, it's totally sealed off.

With the pump off the red food coloring sits stagnant no matter where I put it. Which frustrates the bleep out of me!
 
Update: I believe I have found the leak, it was where the skimmer attached to the concrete, where nearly everyone with a slow leaking gunite pool has a leak. I just couldn't see it with food coloring. Just bought the pool putty stuff. If anyone is searching for a slow leak in gunite pool: let it drain until it seems to stop, look closely at where the skimmer attaches to the concrete, don't use food coloring use the special made pool dye.
 
Weird ... Good that you located the leak. The idea behind using the food coloring was specifically for a suction test not leak detection. As I posted:

"Nothing wrong with using a tube or two of food coloring for a quick suction test at the skimmer or MD.

Open the Skimmer
Remove the basket
Squeeze a couple of RED drops into the skimmer
Watch it get sucked into the suction line"

Now, although you might get luckly, very very luckly, using it for leak detection, it doesn't work because once the droplets mix with the water ... you're basically trying to locate a leak with colored water ... and that won't work.

Regarding the "diverter valve" & the MD .... Your MD will never have any significant suction as long as that "diverter valve" is removed. Make sure it's the correct one for your specific skimmer and also verify the presence & condition of the O-ring needed for the seal. Once you "leak test" the MD, re-install the valve and adjust it for MD suction.

From what I recall ... you have a single skimmer ... and if the "diverter valve" is actually a MD Float/By-Pass Assembly, then maybe the previous H/O removed it because he/she got tired of having to remove & re-install it each time the pool was vacuumed.
 
CNJ_EC said:
Regarding the "diverter valve" & the MD .... Your MD will never have any significant suction as long as that "diverter valve" is removed. Make sure it's the correct one for your specific skimmer and also verify the presence & condition of the O-ring needed for the seal. Once you "leak test" the MD, re-install the valve and adjust it for MD suction.

From what I recall ... you have a single skimmer ... and if the "diverter valve" is actually a MD Float/By-Pass Assembly, then maybe the previous H/O removed it because he/she got tired of having to remove & re-install it each time the pool was vacuumed.
Click to expand...

This is my diverter:

http://cdn1.bigcommerce.com/server3600/76ee1/products/4203/images/25021/L1938__19566.1452961922.1280.1280.jpg

I think it's exactly right that it was bypassed for that reason. Is there a diverter that allows a vacuum line? Otherwise the main drain does nothing.
 
Weird ...It looks like your Hayward Skimmer to MD Valve Assembly is for Skimmers SP1082, SP1084, SP1075 and a few other.

What I would do is verify it by looking at the inside of the Skimmer Cover. Once you've confirmed the Model # then check on-line for the correct fitting Skimmer Vacuum Plate.

The MD Valve Assembly sits in below the Skimmer basket .... the Skimmer Vacuum Plate is designed to sit on top of the basket forming a seal with the wall of the Skimmer ... this way when you vacuum ... you minimize the amount of leaves and other debris from returning to the pump & filter.

Here's a couple of links to view .... and be sure to get the rubber gasket ... not sure if it ships with the plate

Hayward Pool Products | Skimmer Vacuum Plate, Hayward SP1090/1091/1092 | SP11041 | 34835 | 610377047357


Hayward Pool Products | Skimmer Vacuum Plate, Hayward SP1090WM | SPX1090WMVA 610377591751


Be sure

Good Luck!
 
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