Rust Stains on Bottom of Gunite Pool

[kc101]

In January of this year I noticed several small (1-1/2” long) rust colored stains at the bottom of my gunite pool. It was finally warm enough this week for me to dive down to inspect them. I unsuccessfully attempted to remove them w/ a wire brush. They appear to me to be rust stains, although I never found the culprit (nail, screw, etc.).

Does anyone have any suggestions as to how they can be removed?

Thanks

[kelemvor]

In January of this year I noticed several small (1-1/2” long) rust colored stains at the bottom of my gunite pool. It was finally warm enough this week for me to dive down to inspect them. I unsuccessfully attempted to remove them w/ a wire brush. They appear to me to be rust stains, although I never found the culprit (nail, screw, etc.).

Does anyone have any suggestions as to how they can be removed?

Thanks

Try placing a Vitamin C (ascorbic acid) tablet directly on one of them for a few minutes and see if it has any effect. If so, you could probably proceed with a full ascorbic acid treatment.

http://www.poolforum.com/pf2/showthread.php?7923-Stain-removal-via-ascorbic-acid-treatment