RE: Mineral Licks
In addition to the di-cal and cheap dirty rock salt, I add a 40lb bag of powdered limestone to the mix. Try and get powdered limestone with the highest mangesium carbonate content you can, the calcium carbonate content will always be higher. I found one brand of lime that was 20% calcium carbonate, and 10% magnesium carbonate .... it just depends on the source of the limestone.