Diatomaceous earth for calcium?

[irrka]

Originally Posted by estación seca

9210-9600 mcg/L of calcium? That's 9.2-9.6 mg/L or around 9.5 parts per million. That is very little. You can use your tap water for your orchids, with proper fertilizing and supplementation.

But to supplement Ca for the catts? Would the tap be enough without supplementation? Given that they started making those changes in pseudobulbs and leaves within last year I thought meant they needed more?