[metron9]

I have a swimming pool vinyl liner staining problem when adding well water to top up the pool.
I have read about iron filters using green sand, Brim and Filox-R
The Filox-R (75%-85% Maganese Dioxide) seems to be the best product for removing ferrous iron
from water. An oxidizer is needed in the water to react with the ferrous iron and convert it to ferric iron.
I plan to make a filter that will run pool water through the Filox-R and then inject the raw well water
into the filter at a smaller rate of flow to satisfy the oxidizer requirement of the media.

From what I have read it converts the ferrious iron to ferric iron.

Two questions.

Does anyone know the particle size of the resulting ferric iron?
I intend to backwash the media and filter out the ferric iron so that the backwash
water is returned to the pool.

Can the ferric iron convert back to ferrous iron?

This winter we had a very bad staining problem all over the liner, green/brown iron stains.
We used "Iron Out" powder the kind people use in water softners. In a 30,000 gallon pool
we poured about 15 LBS of this product along the walls. It removed all the iron stains
and it was very interesting to watch. There was a large dark green translucent cloud that formed
and held together near the bottom as if it were heaver than the water. We could not see the deep ends bottom
I added a few pounds of diatom powder to the filter as it was running and closed the skimmers so that only
the bottom drain was open. After about 30 minutes the pool was crystal clear and the cloud of green
was trapped in the filter.

Questions on what the stain really is.

Ferrous iron is dissolved and clear in the water, does the  ferrous iron convert to ferric iron when it
bonds to the vinyl and dos the iron out product re dissolve the stain (ferric iron) back into the water?

We used an iron magnet product to as I understand it sequester the iron. Is this sequestering process similar or the same
as what the Filox-R product will do, that is convert the soluble ferrous to insoluble ferric iron?

Last question, is the iron out product still in the water or can we filter that out, does it chemically change
when it interacts with the iron stains?