I've spent the last three years (yes, that's THREE) rebuilding my existing pool that was originally built in the mid 50's.

Lots of problems, lots of solutions, lots of money. The person who is setting up the electrical/control side of the equipment is a Pentair factory rep. He says that to take advantage of my variable speed pump(s), that I need to go with the "Quad" cartridge filter. He says that a non-cartridge filter has 12 to 15 more 90 degree bend in the interior of the filter.

The additional 1080 to 1350 degrees of bends in the filter puts more resistance on the pump, making the speed it has to run higher, cancelling the benefits of the variable speed. The town I live in requires that the filter be hard plumbed to the sewer line with a p-trap.

Someone told me that the quad filter can be backwashed, but that the plumbing for it is "backwards." Thoughts?