Quote Originally Posted by waste
AJ, here might be the problem, Hayward makes some of the best equiptment out there, unfortunately they don't know how to use it. To backwash your unit correctly:
(Obviously, turn off the pump when changing multiport positions)
Put the multiport on backwash, and watch the sightglass for ~clear.
Rinse the filter till it is ~clear.
Repeat until the 'backwash' cycle is ~clear and rinse again. (~3-5 cycles)
Put it on filter for ~ 1 min. and do another backwash/ rinse cycle.
At this point, you've gotten ~80% of the de out, so only add 80% back in, in your case, it's a little under 4#.
Having way too much, or too little, de in the filter can cause the problem you are experiencing and hurt the unit. Try this a couple of times before you replace the grids.

I'm having the same problem (pressure building quickly w/ DE filter) have a few questions.

First, should I bother with the backwash process you describe or just proceed with cleaning the grids now, and use that process in the future?

Second, and more of a newbie question, I have 2 valves I turn when I backwash. The first is a "turn and pull" type valve in front of the filter (is this the multiport?) and the second is an in-line "bypass valve" between the filter and the separation tank. In your instructions, you mention the normal backwash instructions (3-5 cycles until clear), but then you say "put it on filter for 1 min." Does that mean to close both the bypass valve and the multiport valve just as you would when you finish backwashing?

Thanks in advance