Gentlemen, how are you today (other than frustrated, Fog)?
Chuck has said quite a few good things here, and IMO is doing a great job of answering the questions! Let me add a couple of 'why' s to what's been said.
On the matter of the psi rising so quickly - the spaces between the particles of DE are almost the exact size of an algae cell - algae clogs it very quickly, bumping will drop the pressure ~ 5 lbs the first time, and less with each subsequent bumping - 'backwashing' or rinsing out the filter is the only way to get that 'used' DE out. Breaking the filter apart and hosing the fingers will probably get you back to the 10- 15 psi, but with a green pool - you've got to do it often as long as the water is green/ cloudy. [while I'm at it, DE filters use a coating of DE (duh!) to pre-coat the grids or fingers with a material (DE) that won't pass through the 'cloth' but will collect all but the smallest of particles. The collected particals stay on the outer surface of the DE coating and never touch the collection membrane, until you bump - bumping 'shakes' the DE coating off of the cloth and let's it drop to the bottom of the filter tank. When water starts passing through the filter again, this DE with 'scum' on it mixes with the clean stuff that was between the dirty DE and the clean DE that was on the membrane, which opens new passages for the dirty water to flow through, but not as many as a freshly cleaned and recharged coating would be. **bumping does not remove any of the dirt from the filter - unlike backwashing does - it only rearranges the clean and dirty DE to open the flow until the new channels fill up with dirt/ algae)]
Where was I... Ah, too much DE - my feeling is that the # on the plate for how much it holds is correct, but only when the filter has been fully cleaned of DE, if you've only backwashed or bumped and cleared the tank, you've still got a pound or two in the filter and should only add ~80% of the initial amount when recharging (Chuck, I'm sure that your 'wand' gets closer to 95% - adjust acordingly)
Too much DE or too little can cause performance problems, I'll link up some of my old 'gems' () on DE filters at the end of this post.
Chuck, the reason for relieving some air before bumping is because water can not be compressed, but air can - if the tank is full of water and the back pressurre from the run of the lines is too great, forcing the fingers up (and for people who do it backwards) or down can crack the plastic tube sheets - air can be compressed and will do so before the pressure cracks the sheets. So, yes, the pressure gauge will show 0, but you make some by bumping the handle.
I've gone soo far off what I had planned to say... here's some links to my other advise - if something's not covered, please ask![]()
[thread=6811]EC cleaning[/tread]
other DE info
general EC info
Pfwhew! - sorry to go on so long! GOOD NIGHT!!

)?
. [while I'm at it, DE filters use a coating of DE (duh!) to pre-coat the grids or fingers with a material (DE) that won't pass through the 'cloth' but will collect all but the smallest of particles. The collected particals stay on the outer surface of the DE coating and never touch the collection membrane, until you bump - bumping 'shakes' the DE coating off of the cloth and let's it drop to the bottom of the filter tank. When water starts passing through the filter again, this DE with 'scum' on it mixes with the clean stuff that was between the dirty DE and the clean DE that was on the membrane, which opens new passages for the dirty water to flow through, but not as many as a freshly cleaned and recharged coating would be. **bumping does not remove any of the dirt from the filter - unlike backwashing does - it only rearranges the clean and dirty DE to open the flow until the new channels fill up with dirt/ algae)]

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