I have suspected, since I subscribed to this forum, that our pump is too powerful for our filter. 1 1/2 HP pump for Silica I filter. 24 round UG pool! Our pressure never goes up and very little dirty water is backwashed out. Of course, my husband doesn't want to hear it but I am pretty sure this is the problem. The brown stuff is definately not gritty.
We replace the sand every summer. At the end of the season it is white as snow, normal?
Your thoughts appreciated