I've been losing water in my pool since I opened it. I have to add water everyday in order to use the pump. It seems to be about 1-2" of water a day. Also when ever I try to vacuum I have *very* strong pressure but it only lasts for 15-30 seconds then it will suddenly stop sucking. I have to remove the hose from the skimmer and wait for the pressure to build back up so I'll I do this over and over again to be able to sweep up debris.

Would this sudden loss of suction indicate the leak is most likely to be in the plumbing and not in the liner????

This is an IG vinyl pool... 18x36... sand filter......Thanks for any input.....