Looks like there's something up with your D.E.... unless its not D.E. sand.. then you could have a leak in the lines, of which your getting dirt in the pool.
Do you have any air bubbles that jet out, when you start it up?... or while its running?.. this would be a sign of a leak.
I tend to set people up with Cartridge type filters.. that you don't backwash.. but wash out and replace every other year.
The pool you have there is a San Juan Fiberglass Pools.. depending on size, either a Dallas, Pacific, Phoenix, Vegas or (Colorado - discontinued). (I am/was a San Juan Pool dealer).
Cleaner -- if you have a separate cleaner connection on the wall.. those lines typically are plumbed with 1.5" pvc.. If your running the cleaner.. each cleaner has a suction level of which they work best at. too much.. may not work well, to little.. same thing.
IMO... Its best to run ...or 70 drain/30 skimmer.. ... since debris tends to settle on the bottom.. you'll have more crap down lower.. However. you'll need to move it.. if your cleaner hooks up to the skimmer.. to give your cleaner more suction. - for a say.. 2-3 hour time period... ( which I do with automation).
Art Correa
California Construction Co
Sun Splash Pools and Outdoor Living
831-902-8551 mbl
http://www.sunsplashpool.com