Pool Leaking Only When Skimmer Runs

by Mary

My 8 yr old inground 18,000 gal gunite pool has been losing 5'+ water each week. We first noticed it over the summer when we used the pool a lot with plenty of kids jumping about plus hot sun beating down, etc, so attributed it to that. Then, as cooler temps came along, for about 3 months the skimmer was not working at all due to a blockage, and the water loss did not occur during this period.

I did continue to run the filter and my Kreepy Krawly during that period. But again, no water loss occurred. I thought it was because we were not using the pool and the cooler temps, etc. But once we attended to the blockage and the skimmer began functioning properly, the water loss has become readily apparent once more, despite the fact the temps here are still cool and we are not using the pool. The waterr leverr seems to drop fairly rapidly to the bottom of the entrance of the skimmer, but no further.

But then, I dont let it get further, as I know it would be harmful to the system to let it run dry. I can not find any evidence of water around the pool or the pool equipment. Any ideas, other than to call a pricey leak detection service company?

Thanks. And I will visit your website--I have bookmarked it! BTW, I just went out to look at the pool equipment more closely while it is running and I did notice that there is some dripping coming from the filter unit (a Sta-Rite System 3 Modular Media Filter). It seems to be dripping slowly from a few places, especially the air release valve (yes, we have tightened it as much as we can), as well as maybe some bucklehead fitting, and maybe the clamp that holds the top of the unit on to the bottom of the unit.

Its difficult to tell if the water dripping from these last two places is actually coming from there, or if it is just excess water collected at the top from the air release valve that is now dripping down the sides. I'm wondering if it was doing okay when it didn't have the extra duty from the skimmer pushing through it, but now that the skimmer is working well, perhaps we have blown a gasket or an o ring or something!

(This from a woman who is anything but mechanically inclined--I'm reading the owner's manual!). Anyway, If you can correctly diagnose this and it's something I can fix, I'd happily pay you $29!

Thanks for the question Mary

Leak detection can get expensive but I'll first start you down the right, and cheapest, road. Cartridge filters are pretty straight forward. The air bleeder valve should have a small gasket. If you can take out and screw in a light bulb you can replace the gasket. Turn the system off, remove the old and put on a new one. The belly clamp should have an o-ring as well. Check it and replace is worn out. When buying new gaskets it's best to take the old ones with you to make sure they're a good match.

One trick to do when tightening the clamp. Put it around the filter and slightly tighten it. Take a hammer or rubber
mallet and gently hit around the perimeter of the clamp, then tighten a bit more. Alternate hitting the clamp and tightening it. Doing this a few times will ensure you get a good seal all the way around. Also be sure the pump pot lid gasket is good. Replace it if it's broken or cracked.

Skimmers and pool lights are known for leaks. You need to isolate the skimmer. You can simply turn off the valve to the skimmer. If the valve is not marked there's an easy way to figure it out. Turn the valve all the way to one side then gently feel inside the skimmer. If there's no suction you've turned the skimmer suction off. If it still has suction you've turned the bottom drain suction off. The skimmer needs to be turned off for the next step.

This way you still have water flow going to the bottom drain. Get a grease pen and mark the water level then allow it to go for a day then make another mark. You'll see how far the water decreases. Keep doing this until there's no more draining. If the water level is allowed to go under the skimmer then stops, you have your answer. It's the skimmer that's leaking. If it keeps leaking the light may be leaking, if you have one. Worst case scenario is is you have a suction or return side leak in which case you'll need a leak detection company. If it is the skimmer

I did a many pools like this when I had my pool route in AZ. Be sure to turn the system off before turning valves or making adjustments. Look around the filter equipment for water and leaks when the system is on. Bulk heads are pretty easy to install but if you're unsure it's best to hire someone to do it. You can replace the air bleeder valve, pump, and belly gasket for a few dollars. Get some Magic Lube and lube up the gasket if you replace them. Your pool store should have it.

Another test that can be done is called the dye test. You can get Taylor Reagent for testing pH. It's a red dye and your pool store should have it. Simply unscrew the top and put the bottle under the water. Squeeze out a couple of drops right around the skimmer seal. If the dye disappears and goes into the seal you know you have a skimmer leak. Do this slowly and be sure the pump is off. The least amount of moving water the better. Go around the perimeter of the skimmer seal. You can do this around the pool light as well.

Before calling in a leak detection company you can try the above. It may cost about $30 - $40 for the gaskets and pH tester and a little bit of your time but that's alot better than paying a LDC $2000.

If you feel your situation is more complex than this, I do phone consultations for a donation of your choice. It makes things go much faster and many people have found it extremely beneficial, saving them time and money in the long run. All your questions will be answered. I have nothing to sell you so you know I'm not bias.

Pool Consultation

Hope this helps.


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