While I am in the process of trying to clean my pool, I am running the navigator to vacuum some and while doing so, there is dirt/debris going straight back into the pool via the returns, what could be the problem? I just today replace the spider gasket thinking maybe thats the culprit. Now Ima draining the sand filter so I can look at the sand, but draining the water from the sand filter is a slow go. What should I be a looking fer as far as the sand goes???