Calcium Magnesium Questions

[SundayGardener]

Thanks everyone!

My water is really hard. There is a lot of limestone in the area and it comes through the water supply. It leaves white deposits on everything. It's also pretty heavily chlorinated. We also have a water softener (although I'm not convinced it does anything) so that's also a potential problem for orchids. Anyway, I can always tell when I travel because the "foreign" water is so much easier on hair and skin.

I did start out using tap water, then spring water.

What I think are signs of calcium deficiency are purpling leaves and black spots of leaves (cattleyas only). I read the St. Augustine articles on calcium and cattleyas (here's one of the links:
https://staugorchidsociety.org/PDF/C...ySueBottom.pdf
.

I do use K-Lite. I think there is information on paph sensitivity to calcium on the slipperorchid.org, with a list. I DO have either oyster or crab shell on hand--ready for all contingencies!--so I'll try that! I bet I can get my hands on chicken oyster shells as well at the same place where I got cherrystone to make "gritty mix" for potting succulents and such.