What is a "standard" potassium level Mike?
The standard K to N ratio in coated fertilizers here is between (very roughly) .4:1 to.8:1 sometimes as high as 1:1 or more. So I guess somewhere in between these figures I would consider average. I'm sure it would be similar everywhere else.
So for aruments sake, lets say .5:1 or potassium at half the nitrogen levels. The osomocote formulation I'm using on all potted orchids at the moment is:
16.6-2-6.6+2%Mg. No Ca so I sprinkle course Gypsum crystals for the Calcium and that's it--once per year. with the paphs, Pillip,roth,exul, are getting the same. All the others (paphs) get Miracle grow ''Max Feed'' :20N - 2.2P - 9K - 5%Ca -.5%Mg. (The lowest in K I could find) mixed at 0.2 dSm then I add various organic preps to bring the EC to 0.3 dSm. The mounted stuff get the same but EC is double or more.
I also use kelp now and then (4%K)
I'm not sure how much K the original MSU had but from what I remember it had K at more than 100% of the N? That's much like your standard hydroponic mixes with I used to use before I moved here 4 years ago. The water there was very hard. It left terrible lime deposits on all the leaves, pH was 10 at times.
So maybe my fert at the moment is on the lower side of standard but still plenty of K. I don't know the Ca an Mg content of my water but I would guess it is low. The mains water is slightly acidic. EC is 0. For the paphs I use 50/50 rain/town water.
I was generally addressing poor growth, chronic disease, and poor long term results (the boom and bust syndrome). Short term problems revolved around poor growth and high mortality of seedlings in compot.
I find that when I have these problems (and everyone does) It's usually caused by neglect of some kind. The fact that we try to grow orchids from so many different climates and habitats in one area with the same techniques we're always going to have problems. When I see the boom and bust thing Its always caused by deterioration of the p/media. The substrate begins to decompose and it takes the roots with it. You wont see that happening in a plant thats growing faster than the media deteriorates. It seems to consume whatever is being decomosed and stays healthy. Thats why its easier to manage a large plant in a small pot than a small plant in a large pot.
And I can remember your earliest posts on the site that were all complaints about certain plants, or groups of plants.
Thats cause I didn't know what the hell I was doing (mainly with brachys)
You definitely have a large collection of long term awesome plants. So I don't always understand where you're coming from when you mention problems in your culture, and then discount any proposed solutions.
Thats what I've been trying to say....That the long term plants have always had a good amount of K.