Cellulose Fiber Clear conversion

Clean/fresh DE sloughs off of the grids too. The nylon fabric in a radial style DE filter is probably a little bit better than the polypropylene material used in vertical cartridge style DE filters. But it all sloughs off when clean. My procedure is to clean and recharge my filter but then I run my pump for 24 hours straight after cleaning. That way the DE coats everything and is more likely to pick up enough particulates to make it stick better. As was posted above, dirty DE tends to stay stuck on.

I doubt there is any harm during startup. The in-rushing water into the filter instantly kicks up the DE on the bottom and the filter material will be coated within seconds.

With a Sand Filter, the Fiber Clear should sit on top of the sand, but it is a fine soft powder, so it may get mixed up inside the sand, not sure. I know that is does not come back into the pool because I had shut off one side of the 8 returns at one point (4 of them) and close the 2 step returns, and patiently sat by the 2 returns left (which were near the skimmer) that I dropped in the powder. The pressure was extreme and I only waited one minute before shutting opening up all the other returns. This kind of tells me that it sits on/in the sand and works slightly different than the DE filter.

Its a soft white powdery material when dry, but expands and forms a "mat" on the top of a sand bed when wet. Most, if not all, will be removed at the next backwash as it is so light. Any that may be left over will have no effect on flow or filtration.

No more DE for me. I am switching over on my next filter clean to Fiberclear.