Guinite pool,leak?

[Jonette2]

So its spring, time to pull the pool cover off and get things started. In the fall we drained our guinite sw pool to below the jets and covered with pool cover. Same as previous 5 years. Each previous year we pulled the tarp off and water level was where we left it. Well, today, pulled the tarp off and the pool is empty. Is there a leak? Help please

 

[Texas Splash]

That does sound like a potential leak. Last winter was incredibly brutal, and some pool owners experienced changes in their pool/equipment they never saw before, so now would be a good time to investigate. If your pool is completely empty, then I'd have to assume there was a place in the lower portion of the shell that cracked and allowed water to escape, or perhaps you have a Main Drain (MD) and water got out from there. If it is the MD, you have the option of finding the exact placed where water is getting out, or simply plugging that MD altogether. Many pools do just fine without a MD, so it's up to you if that's the case. I suspect there are pool companies in your local area who will also perform pressure tests or use leak detention equipment to find the source of a leak. Very unfortunate way to start your swimming season, but hopefully it's not that bad so you can get the pool full again soon. It's never a good idea to leave the pool empty for very long. Good luck and keep us posted on your progress.

 

[Jonette2]

So, it does have a main drain, at the bottom of the deep end. 11 feet deep. When we removed the tarp, there was about 7 inches of a small pool of water at the main drain. My husband pumped it out and the next day, there was about 10 inches of water there again. It did not rain, where did it come from? Someone told me there is a hydrostat just below the main drain and it could be faulty. What is your opinion?

 

[Texas Splash]

Someone told me there is a hydrostat just below the main drain and it could be faulty. What is your opinion?

That is a possibility. Good you mentioned it. Keep in mind the main purpose of that valve is to let ground water come back "up" to prevent the water table underneath from pressing too hard on the bottom of the pool with nowhere to go, thereby damaging the pool. It relieves that pressure underneath.

But they can go bad. If it is bad, now if the time to change it. You should be able to remove the main drain cover to get to it. You can perform a food coloring dye test it to confirm a leak if you wish. Although since you're there, it might be good just to swap it out regardless so you don't have to worry about it for a few years. If the valve is bad when the pool is full, you would have to can use a plug, expandable or otherwise (in scuba gear unless you drain), to seal the opening while you look for a replacement. Since the water is so low now, you probably won't need to mess with plugging. Just replace the valve and press on. Some valves might require a special spanner wrench tool that gets down into the groove of the valve.

Here's a video of one replacement if you've never seen one: Replacing a hydrostatic valve - YouTube

 

[Jonette2]

I am understanding, yet I have another question. How do I tell if the hydrostatic valve is good or bad? This one flexes up and down when pushed.

 

[Jonette2]

Our hydrostatic valve is smaller in diameter and a bit taller than what I see in the video. It's also silver, not white. It has a washer attached to the top of it. We have a small bilge pump we placed in the main drain to remove the water, so we can view the hydrostatic valve. When we pump the water out and remove the small pump, the water returns up thru the hydrostatic valve. My question is, if we fill the pool, and the main drain hydrostatic valve malfunction, will the groundwater continue to enter the pool thru that valve? Or if the valve is malfunctioning the other direction, will the pool water run out of the pool into the soil?

 

[Texas Splash]

I'm going to request another set of eyes on this topic specifically to make sure since I don't work with those valves a lot. But it's my understanding that when the pool is full and a hydrostatic valve fails (bad seal, stuck due to debris, age, etc), you can experience a leak - much like what started your thread to begin with. Once the water was drained, ground water from below came back into the pool because there was no weight to press it back down. In any case, it's not very often pool are drained completely, so I would consider replacing the valve now. But I'm going to ping another expert or two.

 

[Jonette2]

I'm thinking the same thing. My husband is arguing with me. I think he just doesn't want to replace the valve. I think we are going to have to, or it's not going to hold water. He's got the pool filling now. We'll see if it holds. I think it's already leaking, the level of the water doesn't seem to be rising.

 

[Texas Splash]

At some point, before filing too high, you might want to stop long enough to keep everything very still and apply some food coloring or dye around that drain & valve. See if it gets sucked-out.

 

[PoolguyinCT]

Post I picture of your hydro please.. you say it’s not white??

How old is the pool & is the main drain plastic or metal?

 

[PoolguyinCT]

That is a possibility. Good you mentioned it. Keep in mind the main purpose of that valve is to let ground water come back "up" to prevent the water table underneath from pressing too hard on the bottom of the pool with nowhere to go, thereby damaging the pool. It relieves that pressure underneath.

But they can go bad. If it is bad, now if the time to change it. You should be able to remove the main drain cover to get to it. You can perform a food coloring dye test it to confirm a leak if you wish. Although since you're there, it might be good just to swap it out regardless so you don't have to worry about it for a few years. If the valve is bad when the pool is full, you would have to can use a plug, expandable or otherwise (in scuba gear unless you drain), to seal the opening while you look for a replacement. Since the water is so low now, you probably won't need to mess with plugging. Just replace the valve and press on. Some valves might require a special spanner wrench tool that gets down into the groove of the valve.

Here's a video of one replacement if you've never seen one: Replacing a hydrostatic valve - YouTube

That’s diver Mike!!!!

 

[Jonette2]

The pool is over 20 years old. The main drain is white pvc looking, but the valve is different. Has a screw and a washer attached to the top. I seen a picture online of one like ours, I'll try to find it again.

 

[Jonette2]

https://www.poolpartsonline.com/p-104191-sr-smith-hydrostatic-relief-valve.aspx?utm_source=google&utm_medium=ShoppingFeed&utm_term=ProductListingAds&utm_content=AllProducts&utm_campaign=GoogleShopping&gclid=CjwKCAjww6XXBRByEiwAM-ZUIAVNze-_RDoNgW7--Rh1BwcMSwnl2J5xc9_hPvEw-cnqcHOEk7ea7hoCI7cQAvD_BwE

 

[Texas Splash]

Ooooh. Pricey little buggers aren't they? I didn't realize. Curious ... did you do a dye test on the existing valve to see if water is trying to leak back "out" now?

 

[PoolguyinCT]

https://www.poolpartsonline.com/p-104191-sr-smith-hydrostatic-relief-valve.aspx?utm_source=google&utm_medium=ShoppingFeed&utm_term=ProductListingAds&utm_content=AllProducts&utm_campaign=GoogleShopping&gclid=CjwKCAjww6XXBRByEiwAM-ZUIAVNze-_RDoNgW7--Rh1BwcMSwnl2J5xc9_hPvEw-cnqcHOEk7ea7hoCI7cQAvD_BwE

That’s reasonable, considering how much time them spend unattended- I don’t like the cheap plastic hydros, they are chincy.

 

[Jonette2]

So, good news, my husband put about a foot of water in the pool and after sitting a day, some drained out. He's agreed it's faulty.
After searching online I realize the old valve we have is quite expensive, yet the newer pvc types are 20 bucks. We are going to pump the water out and pull the old valve and see what the thread measurements are like and see if we can replace it with a more modern cost effective one. That metal one is 100 bucks everywhere.

 

[Texas Splash]

It's great you confirmed what to fix. As for the quality of a particular valve, that's out of my area. But the others watching this thread may have a suggestion two to help to ensure you are getting a quality product that won't require a repair anytime soon. Let us know how things turn out after the repair. Good luck!

 

[Geebot]

So its spring, time to pull the pool cover off and get things started. In the fall we drained our guinite sw pool to below the jets and covered with pool cover. Same as previous 5 years. Each previous year we pulled the tarp off and water level was where we left it. Well, today, pulled the tarp off and the pool is empty. Is there a leak? Help please

No plaster damage?

 

[x Wild Bill x]

Just some food for thought, but that current metal valve in your pool has lasted for 20+ years and costs $130 to replace, using a new plastic valve saves you $110. If both valves last the same amount of time the new metal valve costs you an extra $5.50 a year. If for some reason the plastic valve fails before the metal one would have you will be spending more in water and chlorine alone to replace it than you would have saved buying the plastic one in the first place. If this was an easy to get to, simple to replace part I would certainly go with the less expensive one. But given it's location and what you need to do to remedy it if it fails I would personally go with the proven design, but that's just my opinion.

 

[PoolguyinCT]

Just some food for thought, but that current metal valve in your pool has lasted for 20+ years and costs $130 to replace, using a new plastic valve saves you $110. If both valves last the same amount of time the new metal valve costs you an extra $5.50 a year. If for some reason the plastic valve fails before the metal one would have you will be spending more in water and chlorine alone to replace it than you would have saved buying the plastic one in the first place. If this was an easy to get to, simple to replace part I would certainly go with the less expensive one. But given it's location and what you need to do to remedy it if it fails I would personally go with the proven design, but that's just my opinion.

Buy nice or buy twice..