I'm starting to think I have a hole in my Apollo 52-2 DE filter. Opened the pool this weekend (water was crystal clear thanks to all the guidance here) after my first self close last fall. Everything was quite smooth and after my initial vacuuming of worms, bugs and other grime primed my filter with DE. the next day I have what looks like sand all over the bottom of my pool. I'm thinking its the DE that I added. Is there anything else besides a hole that could have caused this (adding DE too fast, adding too much, etc)? Other than a crack in the PVC elbow at the bottom of the unit 2 years ago when the pool company closed it I haven't had any issues with the system. It's $550 for a new grid assembly, or I can buy new grids for $375 and rebuild. Any guidance on how to identify if it's a hole in the mesh over the grid (don't visually see it when I look at it) or other issue?