I've got an in-ground pool with a problem that has recently started. I noticed DE on the bottom of the pool.
I have already disassembled my filter (Pentair 2000 series), and cleaned off all of the grid (less than 6 months old). There are no holes to be found.
I did a little research and have discovered something interesting. When running, my filter operates properly and DE does not come out. However, when I turn the pump off, I've noticed the inspection window of the pump and the skimmer area begin to get cloudy with DE-infused water. Then, when I restart the pump, a burst of DE comes out. I've had a pinhole leak in my filter output pipe for a little while but this DE problem has started in the last week. The only other thing I've noticed is a sucking sound coming from the bottom of my filter where the integrated backwash valve is.
I've read some of the other threads but I was hoping for a more technical explanation so I can order the right parts and only disassemble my filter / valve once to fix this.