Thanks Ben. I didn't realize that my pump/filter were mis-sized (the manual says the acceptable flow rate is between 73gpm and 98gpm). I had assumed this was okay since the HR in HRPB30 stands for 'high rate'. I will look into buying a smaller pump.

I was kinda guessing that either I missed a problem with a lateral or the hub or I somehow damaged the laterals when I put the new sand in (I followed the instructions and filled it 1/4 way with water). But my main question for the forum is 'Do the tiny mesquite leaves blowing back into the pool indicate that something else really serious is wrong with the filter or could they also be caused by a broken hub/lateral? I don't want to spend a lot of $ fixing the lateral/sand issue only to find something else is also wrong. At this point should I just bite the bullet and buy a new filter or is there anything more I could do to diagnois this?"

thanks again,
Dan.