My pool is in need of resurfacing. It has been painted a couple of years ago but the paint seems to be "leaking" and give a chalky look to the water which is made worse by my automatic pool cleaning device. I have heard of "diamondbrite" or something like that and a man came out to see it and wanted to sell me a job with it and when the price was over my budjet he offered to resurface it with another substance he said would look very good but he could give it a 5 year guarantee versus the 10 year one with diamondbrite. What do you think? Would the present pool surface have to be sandblasted off before the job could be done?