Mg and/or Fe deficiencies

[DavidCampen]

Softened water is great as input to an RO system. Why not build your own RO system.

[Ray]

Originally Posted by Leafmite

Bark, sphagnum, CHC, all are slightly acidic and contain nutrients that feed a plant as they break down but the rock, unfortunately, breaks down far too slowly to help my orchids much and provides a different pH.

If you think the degradation of your potting media are doing anything significant toward providing nutrition to your plants, you're fooling yourself.

Mineral nutrition is a complex subject, and what aplies to more terrestrial plants may be totally incorrect for epiphytes.

Sometimes mineral deficiencies in one ion give symptoms that look like deficiencies in others.

In other cases, a shortfall in one nutrient ion can cause deficiencies in others, by preventing the uptake or use of another.

And, if that's not confounding enough, sometimes an excess of one can interfere with the uptake or use of another. Potassium, for example, is a necessary ion, but to much can interfere with calcium uptake.

[Leafmite]

Thanks for the suggestion, David. I will have to research it and whether it is a good choice for all the plants.
Ray, yes, it is complicated. PH? I actually use bark and the moss in my mixes for plants that need a low pH soil as it really helps to keep it low.
Thanks everyone! This has been a great discussion!