The mixing chart listed on the web-site identifies the # of gallons treated per can. What size cans does this refer to? I purchased the Premium in 16 oz cans. Is the chart for 16 or 32 oz cans?

The mixing chart is actually designed to take into account the varying size of cans that the products come in.  If you are blending for Marine or Professional, “1 Can” on the mixing chart refers to 32oz.  If you are blending with Premium, “1 Can” on the mixing chart refers to 16oz. You will also notice that next to each name (in small font) there is a can size for reference.