Pool leak

[Mnkwon]

Hi,

i have an inground gunite pool. My husband has a lot of business trip, so sadly taking care of pool is my job. But i have no idea and knowlege about pool. I hire a company for maintenance of pool. Several days ago, I found my pool is losing water.

When i noticed the water losing, I performed a bucket test. When i turned off the pump, i did’t lose any water. But i turned on the pump for 6 hours a day, the water level has dropped down 1/2 inch a day. My pool care guy suspected that the leaking is from cracks between stones of step-like waterfall from spa down to pool. I can’t aggree with him. Usually, the water level is lowered about 1/2 inches down as soon as the pump is turned on and then the water level is returned back to the original level after the pump is turned off, i know. Is it right? But the water level of my pool was not returned back even after I operate my pump for short period, only 30 minutes. I think it means the water leaking is not from the cracks. What is the problem in my pool? Which part makes water leaking?

Please give me an idea to solve this problem, Please..

 

[Texas Splash]

Hello and welcome to TFP! Finding a leak can be frustrating, but you have to be methodical and take it one section at a time. For example, usually we'll shut down all power and simply watch the water level. Perhaps plug the suction and return jet holes as well to ensure the shell is not leaking. Then open the suction hole to see if the leak is in the line from the skimmer to the pump. Or open the return jet holes to see if the leak is on that side. When a leak seems stronger while the pump is on, we lean towards the pressure side since water is pushing outwards with lots of pressure. So we look for wet spots in the ground or anywhere else the water is being pushed back to the pool after the filter. In your case with the waterfall, if there is a leak outside of the rock area I would think you would see something. If the leak was on the suction side from the skimmer to the pump, you may not lose water unless the pump is off. When on, you may see air bubbles in the system, or the pump would not prime.

These are some starter ideas that I hope will help you. Take a look at the TFP Pool School - Leak Detection page as well. Keep us posted and let us know if you have any other questions. Good luck!

 

[Mnkwon]

Thank you for reply.

I have some water loss while the pump is on and no water loss while off. I looked for the outside of the waterfall rock area. Visually there was no crack, but I carefully sealed the surface between rocks with a clear waterproof silicone caulk. I will check again the water level when i turn on the pump. If i still have some water loss even after waterfall sealing, is there a leak on the return line from filter to pool? If yes, how can i find a leaking spot of the pipe under deck? Is there any way to fix without digging? I am really looking forward to your advice.

 

[Texas Splash]

If you suspect a leak in any of the return lines (filter out back to the pool ands return jets), that can get tricky and you may need help. Sometimes we see a bad line because the water is leaking out making the soil soggy. If it's leaking under the decking you may not see it as well or notice it right away. For those that have special tools, they may be able to plug the lines and insert some low compressed air to do a pressure check and see if it holds. For others, they end-up calling a leak detection company who can do that for them to at least confirm where the problem is located. If a return line is bad, it would require digging and repair. There's just no way around that I'm afraid.

Also, you don't have your signature loaded with your pool type and equipment, but it you have a filter that uses a multiport valve, it would be good to make sure the valve is not leaking water to "waste" mode without you knowing. That could also result in water loss.