A customer of mine was told by the installer of their pool that I should not vacuum through the DE filter. I've never had issues in the past with this, so I'm wondering if there is any truth to it, or if it is the installers way of B.S.ing their way out of being responsible for selling them a crappy system. If you can't vacuum through a DE System, how are you supposed to vacuum? If anyone has seen official literature from a DE Filter manufacturer discussing this issue, I'd love to see it. Anyone have any input on this?