What type of coping do you have ? We had a pool built 4 months ago and had a SWG put in. We also selected a flagstone coping that matched the color in our tile very nicely. One problem, the poolbuilder said NOTHING about salt water's affect on flagstone. Destin Pools didn't tell us to seal the flagstone, didn't tell us the salt would break down the flagstone and the grout. Basically, didn't do anything, but take our money and give us headaches that are still unresolved. Be careful when using a SWG.