You need to read our stains guide; ascorbic acid does NOT remove the metal; it just redissolves it. And it IS completely incompatible with chlorine: if there's ascorbic acid in the pool, THEN there's no chlorine in the pool. And, if there's measurable chlorine in the pool, THEN there is no ascorbic acid.
http://pool9.net/stains/
Stain removal is a pain. If water is fairly cheap for you, the EASIEST way to get the metal out of your pool is to (a) dechlorinate, (b) dissolve the stains, and (c) drain the pool and refill. Usually, this isn't an option for various reasons. Often stains are from well water, and the pools have to be refilled from the same metal contaminated water that caused the problem originally.
But, I'm assuming that (a) you have an AG pool and (b) that you're not filling from a well. If that's correct, follow the steps below:
1. Verify that direct application of Vitamin C will remove the stains. (If not post that info).
2. Add polyquat to avoid algae, and stop adding chlorine. You can add bottles of 3% peroxide to speed the chlorine removal.
3. Once the chlorine is gone, add both ascorbic acid (to dissolve the metal) and HEDP to keep the metal dissolved.
4. Keep the pH at or near 7.0; do not let it get super low. Add borax as needed to raise the pH.
5. Once the stains are gone, drain the pool, and then refill. You can use any leftover polyquat to prevent algae till the pool is full.
Good luck!
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