How much can pool be drained without causing damage?

[hawkinsrt]

Hi,

I have a 24" above ground pool, 3 years old. Within the first year of owning the pool, the steps/ladder became dislodged from its position and created 6 gashes in the liner. The first repair I used Swimlane underwater patches and they didn't last me through the off season. I think they failed right at the end of April, it was a chilling dip to make a new patch. The second time I used Gorilla glue underwater seal (that was last season, and making sure they were still good when closing the pool). Within the past week, I noticed the pool level dropping so one or more of the patches must of failed but I can't tell which is the culprit just by looking at it. Its 40 degrees here in New Jersey, so checking each one or repairing each one is not really what I want to do. All of the holes are about 16 inches from the bottom. I know there are concerns with the structural integrity of an above ground pool when the water level gets lowered to a certain amount. And the linear can dry out and crack etc. What would you do in this situation? I would prefer to let the water drain out to 16 inches, repair the holes when they are not covered by water, then fill it back up. Would this be a bad idea. I really really don't want to do the polar bear swim and topping it off with the hose everyday seems like a waste. Its also hard to tell how much is draining vs evaporation especially in March with then wind. But I checked a marker over two days and it dropped an inch so that leads me to believe one or more of the patches failed. Also what method of patching works the best? I don't want to be on alert every off season for failed patches.

 

[woodyp]

I would absolutely, positively go lower than 1 foot............and then as shortly as possible for the repair. You already know that liner will dry out. Good luck.
I did that to my last AGP chasing a leak with no issues.

 

[VinnyinNJ]

Personally, I would take the winter cover off if there is one on and let it drain to whatever it wants to. By taking off the winter cover you stop the stress of it pulling inward. I'm no expert but there may be bigger issues under the liner now that water has been flowing. Sand could be eroded away and patching without any idea underneath could cause more issues. I'm not saying remove the liner but once the weather and water warms up you may be able to feel the bottom without numb fingers. I have done things with water in colder weather and fingers do numb up rather quickly.

 

[hawkinsrt]

I would absolutely, positively go lower than 1 foot............and then as shortly as possible for the repair. You already know that liner will dry out.

Did you mean to say you would "not go" lower than 1 foot?

Personally, I would take the winter cover off if there is one on and let it drain to whatever it wants to. By taking off the winter cover you stop the stress of it pulling inward. I'm no expert but there may be bigger issues under the liner now that water has been flowing. Sand could be eroded away and patching without any idea underneath could cause more issues. I'm not saying remove the liner but once the weather and water warms up you may be able to feel the bottom without numb fingers. I have done things with water in colder weather and fingers do numb up rather quickly.

Removing the winter cover is a good call, or at least that line of thinking makes sense. To your suggestion about "letting it drain to whatever it wants to", would using a garden hose to help it along help protect against the liner drying out and sand eroding? The drain has to be comming from one of the patches, so would it make more sense to get down as fast as possible, patch everything dry, then fill back up? The less water is going down the inside of the metal wall the better right?

 

[woodyp]

Would "NOT"! My bad.

 

[hawkinsrt]

Couple of additional questions. Is it worth it to have the pool drain to the suspected patches in order to patch them dry or just put some fishing waders on once it gets to about 3 feet or so and patch the holes while they are still underwater? I'm going to use the Box #100 this time which seems to be the most reliable. Also, how long is too long for the pool to be that low? It leaving it low for 2 days after the repair ok to make sure I actually found the hole?

 

[VinnyinNJ]

From everything I have read a pool is designed to hold water in not to have pressure pulling in from the weight of a pool cover with water/snow ... well here in NJ we really haven't had snow unless you're in the north east region. Here's my thoughts on letting the pool drain naturally - it will stop leaking when it reaches the leak point - you can then determine which patch is bad if it isn't obvious. I fixed a leak in my hot tub that way along with seeing where the water was coming from on the deck. If it's a slow leak probably no damage to the sand is happening; I had a gash develop that definitely moved sand around.

I don't have any experience with an empty pool other than when it is first installed so I can't say what will happen. If you are convinced that it is definitely a patch - buy a submersable sump pump and it'll do the job FAST! I use one for taking water off the pool cover and taking water out of the pool when closing. I also have it as a back up sump pump in case mine goes out.

 

[Mdragger88]

If the pool is buried at all do not drain lower than the surrounding ground.
Otherwise around 18” shouldn’t be a problem if you move quickly to keep the liner from shrinking/shifting. The more water you can keep in the better. The waders are a good idea. Rounding the patches should help keep them from rolling/ peeling up around the edges.

 

[woodyp]

And lots of folks say a larger patch over a smaller one is good insurance.

 

[phonedave]

Couple of additional questions. Is it worth it to have the pool drain to the suspected patches in order to patch them dry or just put some fishing waders on once it gets to about 3 feet or so and patch the holes while they are still underwater? I'm going to use the Box #100 this time which seems to be the most reliable. Also, how long is too long for the pool to be that low? It leaving it low for 2 days after the repair ok to make sure I actually found the hole?

This is what I would do. You want to drain it as little as possible. Get some waders, and drain it to a point where you can stand it in to make your repairs. I would also go with a pump to remove whatever water you need to. Not only is it faster, but it is not going down the inside of your wall and washing out who knows what around/under your pool.