I have a skimmer with two holes in the bottom. One I know is the regular suction to the filter, but what is the other one for. The problem is that a rock dropped into that hole. I can see the rock and can partially get some screwdrivers on each side but can't get it out. So actually I have two questions:
1) What is second hole for?
2) Is there a way to get a rock out of it (i.e. reverse water flow, etc.).