chlorine tablet brown spot on fiberglass

[jan forbes]

I have a brown spot on my fiberglass pool where a chlorine tablet lay for a day I have tried lots of absorbic acid and oxalic acid nothing will remove it does anyone have any ideas???????????

[Pool Stain]

I have heard that buffing paste used for car paint will remove the stain. Never tried it but it may be worth a shot if all else fails.