What I would like Ray or other experts in the chemicals that plant (orchid) growers use, is to downsize it to the understanding/restrictions of simple in-house growers/small time collectors. I hear the word PPM my eyeballs roll backwards and I say, "Oh he means a teaspoon"-- meaning the language is adapted to the company/large greenhouse grower.
I understand what you’re saying, but I’m going to disagree with that statement. It’s one of the reasons I have issues with YouTube “gurus”, and some of them tell you to use “so many pms”, measured with a TDS meter, which automatically makes the number useless, while sounding authoritative.
If someone just says “use a teaspoon” without narrowing it down with more details, you really know nothing. A ppm is a true measurement of concentration, and it’s easy enough to convert that to a volumetric measurement. It’s analogous to me saying “the plant needs to be 15 degrees warmer”, without specifying the scale, only far more nebulous. With the scale provided, you can easily convert it to something easier to grasp.
Most online “instructors” tell you “what” to do, but provide very little about the “why you should” aspect. Unfortunately, that seems to play well into the minds of the “dumbed down society” we are becoming.
Incidentally, 8/%N in ANY fertilizer gives you the teaspoons per gallon for 100 ppm N. 9.2/%N gives it in ml/L. For example, with K-Lite, 8/12.9=0.62, which can be rounded to 1/2 or 3/4 tsp/gal, keeping you in the 75-125 ppm N range I recommend for weekly feeding. Had I just said “use one-half teaspoon” and you had Miracle Grow 30-10-10 on hand, you’d have fed your plants at 2.5x that rate!.