My niece said she used Tums and they did not help on her tomatoes.

I haven't done it, but I thought about mixing some lime with water to make a slurry and then watering it in. I thought it might be better to make a slurry than to put it on dry.  If you want to try calcium carbonate, I am wondering if you want to try mixing with water, and then putting it on...... I just wonder if mixing with water might make it easier to get down into the root zone. just a thought I had.