When my pool pump engages it does not suck water, both sump and skimmer valves are open, the main controller is switched to filter and both filters are clean I have filled the filter by the pump with water and tested, the impala does suck that water through.
I have removed the Skimmer valve and all pipes are clear of water. I hoovered the bottom of the pool last weekend and it all worked fine.
The big fibreglass filter ball reads zero pressure.
I have run the pump very quickly with all valves closed and there is still no change in the pressure guage
Help, I don't want my pool to turn green or have to spend a fortune on an engineer.