Well, the Dolphin picked up a bunch of gunk but as is usual with it, it didn't cover everywhere. I have an idea what may be complicating the cleanup. It appears I need a new multiport gasket. I backwashed a bit ago and the valve made a weird noise and some water was still coming out of the return. I had a little fountain sprayer on the return is how I noticed it. I took the top off the valve and noticed that the gasket isn't totally seated in several spots and is twisted over a little. I'm thinking that some of the water from the pump is going past the filter and back into the pool instead of all of it going to the filter when it's operating normally. So, this would cause the some of the dirt that's sucked up to be blown back out into the pool and settle on the bottom. At least that's my thinking at the moment. Does that sound plausible?

Thanks,
Stacy