New growth on cattleya is black...what's going on?

[Nexogen]

Originally Posted by silken

My Toshie Aoki new growths die off as pictured in one of these symptoms. But I started adding calcium and mag. a year ago to my orchids. Does it take a long time to have a positive impact? Or maybe I don't use enough. Our water has enough minerals in it that there should be some in it too.

Calcium is deposited in plants cell walls during their formation, once incorporated into plant tissue is immobile so a constant supply is necessary for continued growth.
Calcium deficiency can be caused by; too much potassium, over fertilizing, the nutrients can be there but the roots can’t take them in, to make sure your plant is getting what it needs, keep media pH to 5.2 and 6.5.
Higher EC levels in the nutrient solution reduce the uptake of calcium, unlike nitrogen and potassium which increase in concentration in leaf tissue with higher EC levels. Reducing the EC of the nutrient enhances water uptake and with this, more calcium can be taken up and transported within the plant to developing tissue.