My sand filter is ancient. It's so old the multiport has only backwash, winterize, recirculate and filter. I understand the new ones now have six, rinse being one of them. My question is what is recirculate for? The reason I am asking is because the valve pin broke so to backwash we have to insert a nail to attach the valve handle. I can't tell for sure if we're really returning it to filter instead of recirculate after backwashing. My husband said he's pretty sure. My water is balanced and should be sparkling by now after at least a month of shocking, testing, and running the filter 24/7. However, the return is spewing some serious cloudy water after backwashing. We've discussed sand channeling and changing the sand here and here and I know we have a filter problem, just trying to rule out operator error. Thanks a lot.