Cellulose fiber and backwashing

[Vinnyd0810]

I have a heyward ec40 DE filter. I am using cellulose fiber as my medium. After backwashing, how much do i then add back in? Is it a percentage of the original priming amount or does it just go by psi? To prime, i added 5 scoops(not lb scoops) of the fiber. I already have backwashed twice this season but still unsure about the proper amount and why.

 

[ajw22]

Your EC40 filter manual is attached.

You talk about backwashing but the manual says when the filter powder is totally used, the “BUMP” action makes it possible to drain the used diatomite without backwashing or dismantling the filter.

The manual also says note and record the pressure gauge reading after the diatomite has been added. This is the “precoat pressure.”

I would use the precoat pressure to determine if you added the correct amount of fiber.

If you are not sure maybe you should clean the filter as described in the manual and start over.

 

[Vinnyd0810]

Thank you. I re-read the manual carefully and that is spot on. What i called backwashing, heyward calls cleaning. Same thing. I guess if the bumping is supposed to alleviate the de from the fingers and it can all simply gravity drain out, then you can assume to add as much de as when you started the filter(precoat pressure). I have read that, after a backwash, some medium stays in the fingers of the filter and only to add some or most of the medium back in. I guess the bottom line is to judge it by the psi reading when re-filling until you reach the precoat pressure, whatever amount of scoops or lbs it ends up to be. I’ve put in about 3 scoops as compared to 5(starting) and its been good so far. I guess that tells me that not everything has truly drained out.