I did some searching on here and couldn't find exactly what to do....
Some background: 20x38 IG pool, vinyl liner, Digital Autopilot SWG, Hayward Super Pump (1 hp???), Hayward sand filter, old heater which is turned off, one bottom drain and skimmer, two return jets.
My pool water level is slowly going down. I'd say 1/8th of an inch per day, but i didn't measure specifically. It's nothing drastic, but definitely not caused by evaporation or water splashing out. It hasn't been warm and we haven't used the pool yet. My pool was really full when i opened it up at the end of April and then i noticed a few weeks ago that the water was almost to the bottom of the skimmer.
I refilled the pool exactly to that mark on the skimmer plastic plate, then I shut off the pump this weekend for a few days and the water level remained pretty much the same for a few days. So i turned the pump back on and now the water is slowly going down again. So the leak is somewhere in the plumbing i guess...
I did notice a small leak after the SWG, which i will fix, but it's a small drip....doubt that this would be the culprit. I also did notice some wet spots under the pump and sand filter when the pump was shut off, but now that they are running i don't seem to see that so much. I elevated the heater (even though it's off, water is circulating through it) and it is dry underneath...and very little water on the inside of it...not enough to be leaking anyway.
I do see SOME air bubbles in the pump basket, but really not a lot and no more than i saw in past years. Nor do i see air bubbles coming out the returns.
My next steps are :
1) Skimmer off, bottom drain on....check if water stays same level
2) Skimmer on, bottom drain off....check again
As far as the returns go, is it safe to plug one of them at a time to see if one or the other is leaking underground? Or would that cause damage or too much pressure on the remaining return?
I was wondering if any experts on here have any ideas of how to find this water leak?
Pool is still usable, but i don't want to keep refilling it every few weeks with COLD tap water.