Iron in water source

[BigDave]

Orange sediment on bottom?

[stcohen]

Yes

[BigDave]

Is the filter pressure rising? Are the returns getting weak or is there poor skimmer action? Do you have a 2 speed pump?
It seems clear that the chlorine / raising pH is making the iron come out but it's not settling on the filter as we'd hoped.

[stcohen]

Pressure not really increasing. Returns are strong,1 speed pump (1HP). Had sand in filter changed (200 lb., I think) when I had liner placed
Agree with your assessment, filter does not seem to be capturing much iron.

[FormerBromineUser]

Are you only adding 1 cal-hypo tab per skimmer per day or the half pound max recommended by PoolDoc?

[BigDave]

I'd let the filter go without backwash until the pressure is about 8lbs over clean. The dirtier the filter, the finer debris it will remove. Try to vacuum to the filter and see if the orange stays in. We already know it catches the calcium precipitate. I also think you can let the pH continue to float up to 8. PoolDoc may correct me when he returns but I'm pretty sure that's the plan.

[FormerBromineUser]

BigDave is right! Make that filter work. Also, you may consider adding DE to your filter via skimmer. (See sticky). We will all be joyous when PoolDoc returns in full! Also still wondering about cal-hypo dosage.