I believe the filters are on the same line. I turned each pump off separately and found pressure in each Skimmer, expect SK1, and all returns except R2. These 2 points have both been having difficulties of late. They do pressurize but take awhile.
SK1 Has been lacking pressure with either pump.
R2 Has been showing excessive air bubbling and is the main area of discharge for DE (though I have had it come out of all returns in the past), and is the last to pressurize. Very odd that it is the last to pressurize. the bubbling occured with either pump and was nto stronger with one or the other. Could it be drawing from the backwash if the seal on the rotors has failed? It could be both rotors. They are both a ***** to move. If it was a bad seal i would see heavy water loss right? I do feel that the water loss is high but it is a 65000Gal pool in Southern CA. But still feels heavy. I think I'm going to cut the backwash piping to the drain and put a bucket under it. What do you think? What about from the solar?
SK2 also shows a lack of pressure but being furthest away I am not surprised, though recently there has been better pressure here as well as at the auto vac connection (AV1). Possibly due to lack of pressure at SK1
The pumps fill completely with no cavitations.
In addition to all points having pressure with any single pump running, I was able to see DE pass from one filter to the next when I changed them individually. This happened without passing through the pool and very quickly. (I vacuumed a bunch of loose DE from the bottom of the pool today, so it was loose in the filters and was drawn from one to the other with just one pump running.)
Photos to Photobucket
http://s1202.photobucket.com/upload/albums/Dkoop1/
Hope this helps. I'm begining to feel more comfortable with changing out the rotor valves if we think it is needed.
Danny
Thanks for your help