DE backwash question - how much DE to add

[MichaelT20]

Hi all,

I’ve read here to add about 80% of your de per your filters recommendation when you backwash. I have a Jandy de filter 60sq ft that says 6lbs DE. 80% would be 4.8

The instructions from my pb say to add a full 6lb bag after every back wash.

Should I ignore the instructions and go 80%? Will going all 6lb hurt or just “waste a little de”?

 

[Toxophilite]

80% is a better approximation. Over the years of recharging and breaking down a DE, I would find that each backwash left a little more not removed than the previous backwash, which is what led to the need to the breakdown eventually for a 100% wash and clean. Adding a full charge each backwash will just clog it faster and make subsequent backwashes less effective.

 

[MichaelT20]

Thanks tox we are likely open from April to October ish and so will be doing a deep clean of the filter either at open or close.

I’ll add the 4.8lbs now and see how it goes. I guess it’s not a huge diff.

 

[Toxophilite]

I don't remember the specifics of mine, in the 90's, but I had eventually developed a habit of breaking down every other backwash anyway. Just felt better with the cleaning out of dirty DE muck. Backwashing to a clear window and discharge still left a lot to be desired for clean as to the inside of can and grids. Many times just popping the lid and drain and further rinsing both out through the bottom hole.

 

[MichaelT20]

I split the diff and did about 90% of the bag rather than 80% . Close enough! I hope