calcium in rain water
 

I have just recently gone to just rain water to water my plants. I used to alternate with tap water for the calcium. I bought cal-mag from Ray a bit ago, and need some help learning how to use it. Do you use it everytime you water or just once or twice a month ?
Also, I have read that calcium is very important for Cattleyas, and I would like to know if all orchids need it or is it just mostly Catts ?
What about Paphs which , from my understanding, like pure water. Would they also benefit from added calcium or would that be too much salts for them ?
I appreciate any input you can offer.
Thanks

I give Cal-Mag supplements to all my orchids at every watering.

Calcium is important to all plants, and should be supplied pretty much constantly, as it is not readily transported within pant tissues.

With most nutrient ions, if the supply is deficient, the plant just moves so,e from another part of the plant to the actively-growing tissues. Not so with Ca.

My bottle of Cali magic says to use it every watering so I do. If you are not sure of the amount and it isn't on the label, I am sure Ray can give you that information (or you can find it on his site).

Thank you all for your answers