Ideal nutrient concentrations in mg/L or ppm

[azorahai]

Could someone point me in the direction of where I could read more about ideal nutrient concentration throughout the cannabis life cycle? I've reverse engineered a few nutrient schedules using different bottled nutrients, so I have a rough idea of what is recommended and used (as a rule of thumb, you can usually halve the concentration of most of the official manufacturer nutrient schedules and still meet the plant's requirements), but I'm also noticing a lot of divergence and disagreements concerning its different stages of growth, with some [for example] suggesting a huge increase in phosphorus during flowering (2.5-5 times higher) while others keep it roughly constant. The same with other macronutrients, and even some schedules without most of the usual micronutrients (e.g. Rx Green Technologies suggests only feeding S and Mo, besides the regular N, P, K, Ca and Mg).

I'm trying to gather as much data on this as I can, and eventually I'll tidy it all up and share it with the community for others to use and comment. Thanks!

[YYCannabis]

Ideal nute concentration is not a specific number. The plant tells you what the number should be. Nutrient manufacturers make broad generalizations that will guide the gardener into the general range that a plant will accept, but it’s still up to the gardener to use their eyes to know just how much the plant wants and when.

Each nute maker has their own secret sauce for feeding schedules which makes it confusing.
Then add 10,000 different strains of cannabis and each strains variances in need.
Then factor in how much light is a plant getting.
Then factor in temp and humidity.
....after all that, you can see why following a feed schedule written on the back of a bottle is not a good idea.

[azorahai]

Yes, of course, but there still is such a thing as too little and too much of a certain nutrient during a certain period for an average cannabis plant. Giving your plant only 5 ppm of nitrogen during the late vegetative period will almost certainly result in deficiencies, while giving it 500 ppm will almost certainly result in toxicities. This chart (https://manicbotanix.com/wp-content/...onse-curve.jpg) illustrates what I'm saying. I'm interested in finding out what is this concentration range of maximum yield, so I can experiment with different strains and find out their concentration range of maximum efficiency.

[YYCannabis]

I think you will find that you’re chasing your tail.

Nutrients are only one of five key elements to growing (light/CO2/temp/humidity/nutrients). No single element is something that is an exact number. As I mentioned above, only your eyes can tell you what the plant needs at various stages of growth. And what is “Maximum yield” referring to? How much a plant yields is an unknown number that changes with the slightest variations in the 5 key elements.

To use the example you posted from manicbotanix....what strain of plant are they referring to (indica or sativa)? Daylight or artificial light? What temp is their plant growing in? Etc etc etc.....

I do commend you on taking a deep dive into nutrients and the application levels.