rebedding my EcoWater ETF 2100 pf-10. 10" by 44" tank filter with backwash.
I already added the garnet (rated 140 lb/ft3)
I was planning to add 10 lb sand (100 lb/ft3) per Ecowater manual.
then filox-R (114 lb/ft3). -which is not listed in the Ecowater manual.
The manual includes birm and greensand, which both have densities lower than filter sand, and thus the order would be preserved. I've got the filox in hand, and it seems a good fit for my situation.
But, since the sand is lower density than the filox, does that mean that it will be lifted further during backwash, thus later on the sand will be on the top layer instead of on the gravel? and probably mixed thoughout the filox as well.
Should I just leave the sand out? Please advise.
Noticed on one company's instruction sheet they said it didn't matter what order media was added after the gravel. Perhaps that's because it all gets sorted in the backwash.
While order typically does not matter since the backwash will resort the medias, heavier medias like pyrolox have a difficult time resorting in a timely fashion. Water softener resin and gravel sort in a matter of seconds. You can put the gravel on top of the resin, it will immediately resot to the bottom. Filox and garnet are a much closer so the ability for them to self sort is much more time consuming.
For the most part, garnet underbedding is recommended for pyrolox and filox. here is the information from Clack for that specific media.
Underbed: Garnet #8, #8-#12. #3 Silica. Other materials are also suitable but must keep media from migrating downward and be heavy enough to remain in place during backwash.
How to rebuild a softener http://www.youtube.com/watch?v=8YkJS...ature=youtu.be