Thank you - Calcium, Magnesium, Miracid, and Reverse Osmosis H2O
 

I've use Miracid 30-10-10 (Now Miracle Grow for Acid Loving Plants) to fertilize my orchids for decades believing it had the secondary nutrients Calcium and Magnesium and micronutrients. Maybe it did at one time, but it doesn't now.

About 6 months ago I tossed out a rather valuable C. walkeriana that I loved because I believed it might be virused. Every time a new shoot started, it turned black and died. It went two years without a successful new growth. It was potted in lava rock, which provides no nutrients at all. Also, some of my Cattleya in a bark mix have a mottled yellow pattern on a few leaves, an indicator for calcium deficiency.

I water with RO and rainwater. Y'all commented on my calcium deposit free pots. Well, it turns out that this may not be a good thing.

I'd like to thank the forum members, especially Ray, for the in-depth discussions that helped me recognize and diagnose this problem, for which both cause and effect are clearly present. I moved to Mississippi 3 years ago, and since then have seen the symptoms, but didn't know what to make of them. I thought it might be the Mississippi heat (I've only lived here for 3 years).

k-sci

30-10-10 is a lawn fertilizer designed for grasses.
If Ray helped you I'm glad - I tried to mention feeding everything in a balanced ratio.

30-10-10 is 3 times more N than everything else.

But I am glad you have figured out the exact problem to know how to fix it.

When it was first introduced, Mir-Acid was marketed to orchid growers.

You and others discussed this too, and that discussion also resulted in a change in practices. I was going to use up the rest of my Miracid then change, but decided to switch to MSU for RO/Rainwater immediately.

I was in my early 20s (65 now) when I was given the advice to use Miracid by a miniature orchid collector - ostensibly because it had micronutrients. I don't see anything on the label now to indicate that this is true.

Miracid worked well with tap water for me in Wisconsin, California, Washington state, Des Moines Iowa, and Maine. The water here in Mississippi tastes like wet limestone smells and leaves very hard mineral deposits on everything. We get brown calcium rings on toilets that only comes off with a pumice stone (fun). That's why I switched to using only RO/rainwater.

As a scientist/engineer, I follow a practice you've certainly heard of - "if it ain't broken, don't fix it", so I didn't change fertilizers even though there were copious opinions that it was best. I didn't make the connection between the dead walkeriana shoots and leaf mottling indicating a problem until I ran across a post where someone had the dead new shoots problem (that person was advised that it was due to underwatering). After that, I did some deep repeated searches and reading here about why new shoots turn black and die.

The retail product was marketed for azalias and rhododendrons. There were very few hobbyist orchid growers in 1975. Growers were primarily large operations. I have no idea how it was marketed to them.

Keith - I think you need to "adjust your clock."

I was several years into hobby orchid growing by then and visited orchid societies and AOS judging routinely. The AOS was founded in 1921, and in 1951 several members visited Dr. O. Wesley Davidson (who invented the stuff) at the Rutgers University Experiment Station to see his experiments with orchid nutrition, temperature and humidity.

If I'm not mistaken, I learned about it from ads in the AOS Bulletin.

Hello K Sci,
This is a bit of an aside, but you might find it helpful. Calcium deposits on plumbing (and everything else) can be softened up with acids. I started with vinegar, proceeded to CLR, and now use a bowl cleaner with hydrochloric acid. Wear gloves, use eye protection, and be sure to clean it out before using the toilet! Product is called "Acidic Toilet Bowl Cleaner" Zep brand, found it at Home Depot. It helps a lot, greatly decreases the scrubbing.
Incidentally, it also works great for removing calcium deposits from ceramic pots.
Approximate chemistry is this:
Calcium "Lime" rings are mainly Calcium Carbonate, CaCO3. Hydrochloric acid is HCl. Mix them and you end up with Carbon Dioxide--CO2 (you'll see the bubbles and foam), water--H2O, and Calcium Chloride--CaCl2. Calcium chloride is way more water soluble than calcium carbonate. It dissolves in water and washes away.
Anyhow, that's how it works in Arizona, your results may vary! I had to look up the chemistry, any real chemists out there, please feel free to correct me!
Even further afield, here's some interesting information about using old lime deposits in old pipes as construction material. (Scroll down to the section on "The Aqueduct as a Stone Quarry".)
Eifel Aqueduct - Wikipedia

I have tried acids, but not the one you mentioned. I hate scrubbing toilets with pumice every 6 months or so, so any potential solution is very welcome.

K-Sci

Nice thread. These days - the nice thing is that we have orchid forums for sharing information.

And I think that possibly one of the most effective ways to help orchids is to have every orchid manual or orchid-growing guide -------- have -- at the very front page - the most important and critical details.

Eg. The very start of each guide could have something like ------ consider weak fertilising and also weak mag-cal applications every once in a while. Now --- how much to apply - can always be learned later. But the important thing would be to have the words 'consider such and such'. Consider air-circulation/air-flow around the plant, and through the media and around the roots ------ and reasons for those considerations to be made. And temperature, humidity, local water quality etc.

Other content could involve ------ consider 'root drowning' ------ and have a short section that explains roots that are not adapted to watery and low oxygen conditions, or roots that are adapted.

And mention conditions such as cold plus wet roots (and cold plus wet plants) for relatively long times ----- not so good.

A whole bunch of golden information - all placed at the very front of growing guides ------ could possibly help a lot of people, and also a lot of orchids.

This also includes recommendations about what equipment and material and products (treatments etc) to buy ------- before growing any orchid. Although, of course - some orchids are given as gifts - which in case not much we can do about that.

A couple of orchid nursery owners provided me - when I began to properly (ie. take 2 attempt ------ after my four cattleya type orchids didn't make it ----- when I was a beginner - totally my own fault for being uneducated in orchid growing) get into the hobby of orchid growing - some golden rules and recommendations. I stuck with those ones, aside from from gathering other information over the years. So had never encountered the blackened growth issues before. But ------ I definitely understand that different growers start off with different information ------ not equipped with the same golden information -- so that's understandable.

As a note:
Hydrochloric acid will dissolve dead bodies.
I'm not surprised that stuff takes the brown rings off toilets but I wouldn't use it.
It's sold as brick dissolver here in the UK.
Mix it with bleach and you will create chlorine gas.
Grout cleaners sometimes have the same ingredient.
What HCI does it dissolves a layer of grout which gets wiped away.
Do this enough times and your whole bathroom wall will need regrouting. So it does remove mold and gunk by dissolving a whole layer. It's worth noting why it works, not just that it works.

Because what it does to toilets long term is take away the protective coating on the ceramic and in time you end up with something that attracts limestone even more.