I have a known problem with a lot of iron in my well water. I was talking to Jack's Magic tech support this morning about chemistry levels and one thing he suggested was adding something called filter fiber. This will top dress the sand in the filter and decreases the micron size so that the filter is better able to catch the sequestered? sequested? solids after the sequestering agent has done its job. Is this a good idea? Does it stay in after I backflush or would I have to add more each time I backflush?

We use DE and it works. It comes out when you backflush. The instructions on how to add it are in pool school. I wouldn't think that either one would do anything to remove iron from your water though.

By itself it won't remove the iron. The sequestrant binds to the iron and makes the particles larger so they can be filtered out of the water. The filter fiber increases the efficiency of this. Do you use a DE filter and filter fiber or do you use DE in a sand filter? I assume the latter, a quick check at Pool School gives instructions on using DE in a sand filter.

I believe you need a sequester for metals in water. But once you use then you need to keep using them. Synthetic DE i believe is the same as filter fiber, works, but needs to be replenished after a back wash.
pool-school/metal%20stains

Somewhat the opposite. Sequestrants prevent the metals from precipitating out into visible form but the iron will stay in your water in soluble form. They will not remove ANY iron from your water....only sequester it

Every now and then the sequestrant combined with iron will clump and get filtered out, but that isn't all that common.

Ok. Tech support at Jack's Magic suggested the filter additive to catch the sequestered iron. It sounds like the additive is a good idea but that it won't do much for the sequestered solids.