David Gregg

geeman - Thanks for the responses. That seems to have been it. Next time I drain/refill, I will be certain to wipe the standing water with a towel or my hand - basically leave no standing water so if the plaster dries, it does so in a uniform manner.

For lack of anything else to try, I will be doing just that. It goes against my OCD nature though A few days later.... the stain is gone. Very weird.

For lack of anything else to try, I will be doing just that. It goes against my OCD nature though

Hi Everybody, I have an in-ground spa that is approx 1600 gallons. It is a salt system and has 3M colored plaster (tan color). I drained the water today and refilled the spa. The strange thing is that wherever there was standing water (i.e. puddles on top of steps or water dripping down the wall to the seat then down to the floor, remained as darker areas than the rest of the spa once it finally refilled. I didn't do any acid washing or chem treatments. Simply drained and refilled. Spo the water that remained was the same water that actually dried in other places. makes no sense to me. Anybody know how to correct this? Thanks.