If his spun filter is removing the iron, does it not mean that it is ferric? I thought it was ferrous iron that was difficult to remove if the pH is...
What happens to a membrane over time? Does it clog and get tighter, letting less through or does it wear and get looser, letting more stuff through?...
It really depends what is in the bottom of the well. If the packer leathers are still sealed to the casing, then all the water will be drawn through...