Help in fiinding a leak.....

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.....

There are quite a few threads on here if you search for "Leaking Liner" to get you started . In general you have to isolate the leak between the plumbing and liner first. First thing is to determine if the rate of loss is the same with the pump running or not. As you say you have to add water before running the pump I would assume that it's leaking with it off. That points to the pool but also could be in the skimmer or the piping from the skimmer to the pump. If you have a main drain you should look there as well and if it has a hydrostatic valve in the main drain that would be a good candidate. I just spent a week looking for a leak in my pool and let it leak down under the skimmer while searching for a tear in the liner using a diving mask and a syringe filled with food dye. In the end I had a crack in my fiberglass stairs, so if you have stairs I'd look closely at those as well. Anywhere a fixture is such as a light, return nozzles, skimmer, is a good place to check.

Thank you for replying....I've looked up leaks on the forum and I've seen some great advise on looking for leaks. I just thought if the loss of pressure when trying to vacuum combined with the water leak would indicate a plumbing problem and not a pool problem I could start digging up the line and stop looking at the liner and stop troubleshooting. I shut off the pump last night and did the bucket test by this morning I lost about 3/4". The water level is now even with the bottom of the skimmer. So it still leaked out with the pump off.

I don't have a drain......

Ok well I understand the feeling of dread and frustration but I'd resist digging just yet. One good indicator is the rate of the leak over time as it will slow down when the level gets closer to the hole. I assume you mean you lost 3/4" more than what the bucket test showed in evaporation. I could see the vacuum issue indicating a problem if it was pulling air from a crack in the pipe when the suction became higher and you might well have more than one issue or the water is leaking out the skimmer line. I plugged everything I could on my pool and measured the loss. I put plugs in my returns, my main drain, and my skimmer. If your below your skimmer now then just wait another day and see what happens. Mark the level with a pencil on the stairs if you have stairs or attach a ruler to a fixed part ..main idea is to accurately track the rate of loss so you can tell if it's slowing down or has stopped. If it slows then you start looking around the pool just below the water line etc. I came to understand that this was going to be a week or two project for me and was about to call someone to check my liner with a hydophone. It cost 300 bucks here and they put an electrical charge in the pool and then check the magnetic field which points to the leak. The liner is a good insulator except where it's torn as the field gets grounded by the water going out the hole. Luckily I stuck with it another day and found it myself. Let us know how you're getting on.