Last year I had a problem with getting sand into the pool after changing from Zeobrite to regular sand. This year I pulled the filter apart and dumped the sand and inspected the laterals. They all seem fine and I put the filter back together and added filter balls back instead. I figured if the laterals ARE bad the balls will be easier to remove and toss and then replace the lateral(s) and go back to sand since the balls are cheap. What I think happened is that when I switched from Zeobrite to sand, one of the laterals wasn’t pushed down fully into its extended position, based on what I think I saw pulling the laterals out this year. Is it possible that my sand problem was simply just an issue with one of the laterals not being pushed down into a fully locked position? It wasn’t far from locked but I am now wondering if my problem wasn’t as simple as pushing a lateral down fully.