Losing Water!

[scooter hotrod]

I don't think there are any water thieves on the loose, so I'm assuming its the liner. I have a push/pull valve and there is no water leaking out of the backwash hose when the pump is running, or when it is not running. It must be the liner.....but wouldn't there be tiny bubbles coming up if this is the case. I mean, I'm losing around 2" of water/day or so.

Thanks for the advice....looks like I have some diving to do this evening. I only have a month of swimming left, at best. It will go from high 90's to low 80's by middle of Sept in St.Louis.