Is your pool leaking only when your pump is running? There is a good chance you have a break somewhere in your return jet plumbing. Typically when pools leak when the pump is running and not so much with it is off, many times it is because the water is being forced out of a crack in the plumbing. This isn't always the case but many times it is. You can try plugging off one return jet at a time and seeing if your leak gets worse. When you do this it causes the pressure to become greater and therefore the leak will become greater as well. Just make sure to never plug all the Jets at the same time because this will cause too much back pressure on your plumbing and pump and could cause the leak to get worse and is also very dangerous.
Sometimes pools leak more when the pump is running because it is drawing more water into the skimmer. The area where the plastic skimmer box meets up with the Gunite can leak. When water is being sucked into the skimmer it forces it into that area and causes your pool to leak more. If you are able to turn off your skimmers and run the pump try doing that and seeing if the pool is leaking at the same rate.
Another reason why your pool can leak more when the pump is running is because it is stirring up debris that could be plugging a hole in the pool. Many times as swimming pool can leak because there is a hole or crack in the plaster and Gunite. Sometimes the water movement can stir up debris which would normally plug it and keep it from leaking.
Another reason why a swimming pool can leak more while the pump is running is because it is leaking out the backwash valve. If you are able to see the water come out in a pipe above ground or at the street when you backwash, see if you can see water leaking out while the pump is on. Also many backwash valves have a Clear Sight glass on the side of the valve. Try unscrewing that sight glass and turn the pump on to see if water comes pouring out of the hole where the sight glass was. If this is the case then you will not need pool leak detection. You just need to fix your backwash valve.
One more thing you can try in your DIY pool leak detection efforts is to try turning off the water going to the spa. If you are able to turn off the water return leading to the spa and it stops leaking then you know your problem is somewhere in the spa or the plumbing leading to the spa. You can also try turning off and on different water features and pumps to see if this changes the situation.
We hope this helps you in finding out why your pool is leaking more with your pumps on. If you need help in finding your leak please call our pool leak detection specialists to schedule your free no obligation consultation.