Well, planting season is almost here. I am going to double my tomato crop this year. I have ready access to oyster shells and crushed coral. How good of a calcium supplement would these make? I grow in pots, 22 inch pots - 1 plant per pot. I'd like to just mix in a large quantity of either into my planting soil. I did pretty good last year using a liquid calcium supplement but it was kind of expensive tedious. Hoping to do something cheaper and easier this year.
Paul