Mineral Additions for Custom Water Profile

I made my first stab at creating a water profile for my recent English mild. I weighed out the various minerals utilizing EZ Water Calc and added them to my water at the start of the day.

The complete addition was something along the lines of a couple of tablespoons of material. The water turned a slight milky color which never really went away during heating. I tasted the water and it seemed fine.

After putting the last of the water into the mash for sparging I noticed some of the compounds added had never dissolved even though the treated water had been heated and stirred for the strike and sparge. I haven't a clue which minerals were left behind.

Is this normal?

some minerals will dissolve in water other need to be put in during the mash.

Add some to the mash and the rest to the boil. They need the acidity to dissolve.

Thanks guys. I'll consider this and act accordingly in the future. Appreciate the response.