Brown Pseudobulb. Rot or not?

[Shadeflower]

Ca should be roughly the same as the Nitrogen you feed. If your fertilzier or water already contains enough you will not need to supplement.

Lets say you add 1 gram of a 7-7-7 fertilizer that doesn't contain any calcium and the water deoesn't either. You should add 1.5ml of Calmag in that case (1.5 x 5% = 7.5)

Of just feed it in one large dose once a month. So something like 6ml Calmag per gallon once a month.