Important!! Calcium Deficiency

[Nexogen]

I agree with you 100% but, the problem for orchids is that they are unable to adequately limit their calcium uptake, and will absorb too much of it when available, resulting in cellular pH too high. Some orchids also have difficulties absorbing Fe, Mn, Cu, or Zn, which is more tightly held in alkaline media, another reason why they thrive in low pH media.

[Ray]

Originally Posted by Nexogen

I agree with you 100% but, the problem for orchids is that they are unable to adequately limit their calcium uptake, and will absorb too much of it when available, resulting in cellular pH too high. Some orchids also have difficulties absorbing Fe, Mn, Cu, or Zn, which is more tightly held in alkaline media, another reason why they thrive in low pH media.

Can you describe the effects of cellular pH being too high, due to excessive calcium?

For the most part, epiphytic orchids get the majority of their nutrients from the solutions applied (rainfall cascading through the forest canopy in the wild), and not from the substrate.

[tucker85]

Originally Posted by Nexogen

I agree with you 100% but, the problem for orchids is that they are unable to adequately limit their calcium uptake, and will absorb too much of it when available, resulting in cellular pH too high. Some orchids also have difficulties absorbing Fe, Mn, Cu, or Zn, which is more tightly held in alkaline media, another reason why they thrive in low pH media.

Nexogen, where did you get this information that orchids can take up too much calcium? I haven't read that before.