In general, is it feasible to filter iron out with cellulose fiber which would be cheaper than using CuLator. I think CuLator works but it is expensive. Are some cellulose fibers better than others? It is my understanding that iron needs to go through ascorbic acid to lift from surface and then sequester with HEDP. At that point CuLator will work and also cellulose fiber will work. Is that correct?