Hello, all. We recently purchased a home in the Houston metro area and immediately invested in a replaster job. The finish looked great until the spa had been running for several weeks and we noticed brown stains appearing on the walls directly under the spillway of the pa where there is exposed flagstone. Our pool maintenance man recommended we purchase AquaSeal to seal the stone & prevent staining. This sounds common sense, but are there any drawbacks or any cautions we need to take into consideration? Much thanks!