Good afternoon all! Once again, great info on this site. I am comfortable with the pricing. What I would like to know is what everyone likes to use as far as chemicals? Concrete Bricks Vinyl Aluminum Mind you, I am strictly stayin residential first year and I want to be environmentally safe. Also, what are the reviews on the Dewalt 13 HP 3700 PSI 4 GPM? IS this more than suffice on residentail? Do they hold up well? It comes with a cat pump. Thanks for any info all!!!!!