I love this salt, am on my third 200 gal "set". I do 15 gal weekly water changes. I have found that the best way to make up the water is to put about 13-14 gallons in my rubbermaid container, add the components per the directions to make 15 gallons (I do not weigh, but use the supplied scoops (for the dry components) and cup (for the wet components)) measure the s.g. (it will be high) then add more water to dilute down to 1.025. I used to use the newly mixed water immediately, but now leave it mixing with the powerhead for at least a few hours as I have found that the alk and calcium levels are high when first mixed but stabilize at the reported parameters (approx 470-480 and 9-10).
This takes only slightly more work than a standard salt mix, but the quality of the water more than makes up for it. There are absolutely no precipitates or other "gunk" left in the mixing bucket.