Thanks for the feedback.

I'll open the multiport valve after work and see if the gasket needs to be replaced. If it looks ok, I'll try adding more DE through the skimmer. I think I read somewhere on the forum to put in a little at a time until the PSI rises by 1.

PoolDoc,
Leaves are not going through the grids. The stuff coming out the returns are particles (i.e. dirt and bugs).

On a separate note, I visited the Leslie's closest to my office at lunchtime. After reading this forum for 3 weeks, I felt smarter than the Leslie's workers. HAHA
A worker tried answering a customer's question about the difficulty of maintaining a chlorine level. The worker just tried selling the customer more 3' tabs and didn't ask about CYA levels or if the customer tested their water. I couldn't help myself so I chimed in asking if the person tested their water and what the readings were.

I think I have been reading this forum too much!