Leak?

[dawzlynz]

I bought a home with an inground pool a little over a year ago and I didn't know anything about pools when I bought it. I had a professional open it and he told me how to close it (blowing out the lines with an air compressor, putting anitfreeze in, etc) and I thought we did it fine. Now that I opened it this year I have two problems that I can't figure out. 1- My sand filter cap is leaking around it (screws on the bottom-I drained it and left the cap off all winter) O-rings, gaskets, etc don't seems to make any difference. And 2-My water level dropped about 2-3 inches in two days. Do I have a leak in my lines underground somewhere? How do I find out if I do?

[Leak Detector]

Has the filter cap been deformed in any way; if so, perhaps a new outsized o-ring can help.

The water loss is more of an issue. Firstly determine if the water leak was only at first or if it is ongoing. If possible, let the water escape without topping up. The level at which the water loss stops will show the level of the leak.