Fertilizer choices and water type

[K-Sci]

Originally Posted by Ray

To me, the most significant improvement they brought to “orchid food” was the inclusion of calcium and magnesium, which are uncommon in commercial blends.

It seems very odd to me that we are still discovering this sort of thing in the 21 century. I suppose it is probably because commercial greenhouses don't water with RO. The following is probably not new to the regulators, but I like telling it.

For the last two years I watered my orchids with RO. I had walkeriana growing in scoria where new growths were often dying at about 1/4 inch and the new growth leaf tips often turned black. In fact, I through away one walker that had gone almost 2 years with successfully producing a new growth. A few month ago I began using a calcium supplement and haven't seen new growths turn black since.

-Keith