Pool not filling

[rsoxfan]

I have a spliiover part to my pool and i came out this morning and it was completely drained... and my overall pool leve; is lower... i have no idea what happened... on my autpomatic leveler, the sensor light is lit (yellow) and the "filling" light is lit (green)... could there be a problem with my sensor and that is why it appears to not be filling? again, the sensor light is it (not syre ig that means it's bad or not)

[Larry]

You didn't really give much detail about the automatic level controller your pool has, rsoxfan.

One problem I have frequently encountered in spillover pools, especially when their level is raised, is a faulty check valve that allows the water to drain back to the main body of water when the pump turns off. In some setups the water actually flows back through the filter, effectively backwashing the filter into the pool. That really is not a pretty sight.