Question on lithophytes and lime

[Edward Brookes]

Thanks Blackvine, my mom used to add the crushed eggshell to her African violet potting mix, also soaked the shell in water to produce a foul smelling brew which she diluted & used to feed all her plants - with magnifiscent results. I wonder about the other calcium sources in terms of solubility - I think eggshells would have an edge over them, since they are not naturally designed for long term durability, & so may be more effective without sharply altering pH. I have been adding the crushed eggshell to orchids I repotted recently. Here's hoping for great results. The plants were in meticulously prepared coconut husk chips, with massive root loss after one year. The chips turn to mush under my conditions - subtropical, & getting all the rain that falls, sometimes for days with brief clear spells. I am changing to macadamia shells. I think the eggshells may help as a mild buffer with calcium benifits. Any comments would be valuable