dsk9910

I have a In Ground Pool that after the automatic cleaning system is engaged or regular filter is used sucks all the water out of the out take containment area that goes to the pump until it is sucking air. When this happens the pump is running air at this point and i have to shut the pump off. What I've done so far is: 1. Filled pool above the water line in water containment area that goes to the pump for filtering. 2. Cleaned both the trap filter and the paper filter. 3. Ran it using the auto cleaning system and without using the skimmer. 4. I've filled the pool up several times repeating this and water seems to going somewhere somehow. 5. Uncovered all the pipes up to where they go under the concrete and found no leaks. Please help and if not enough info let me know. David