Last fall before I closed my pool, I was starting to wonder if the sand filter was working. My water seemed to be getting cloudy with sediment. I gave up trying to fix it and closed the pool. I installed a new spider gasket in the multiport thinking that there was a bypassing leak in the filter. I also took all the sand out and checked the laterals, found no problems, and put the sand back in. Now that I am opening the pool and trying to filter again, I still don't think it is working. I have even seen some black sediment blowing back in the pool when I was vacuuming. Is it possible that the water is going into the multiport valve at the top of the stand pipe and not being drawn thru the sand? Is there supposed to be some kind of seal in the bottom of the multiport?