I am having real trouble. I added DE to my sand this morning before I vacuumed the pool. AFter getting half way done, my pressure had gone up from 12psi to 23psi and I had lost a lot of sucking pressure. The basket in front of the superpump had a huge air pocket on top. It seems the more pressure I have, the more air that gets pulled in.
Regardless, I backwashed and rinsed, then added more sand aid and vacummed the rest of the pool.
I heard that you can rinse without backwashing a few times with DE and that will allow you to go a bit longer. I did that this afternoon and pressure dropped from 20psi to 15psi.
I got home tonight and pressure was back up to 20psi so I tried rinsing only and when I went back to filtering, I saw a huge cloud of Crud shooting into my pool.
My sand will not filter out this fine, powdery stuff that I keep finding on the bottom of my pool. Only DE added to the sand seems to trap it.
After adding DE, it is not more than 12 hours later that I have to backwash.
I have also found that there is always a small bit of air coming into the filter at the basket just before the super pump, and I always see tiny air bubbles shooting into the pool through my one inlet.