Nutrient strength vs N-P-K ratio?

Neumann

Active Member
I'll admit, most of my growing knowledge comes from Cannastats which leads me to my question.

I've always accepted as fact Mel Franks nute requirement of 100N-100P-200K-60Mg, although I like and follow pH Imbalances guidelines in the MJ Handbook, so basically I'm doing Lucas with GH Flora. Thing is, when I mix my solution to their guidelines my PPM are much less then what it says in what I read. I know it's not the right thing to do but I use tap (3 stage filtered) water for my grows and it has a TDS of 325 from the tap. When I do the pH Imbalance dosing for flowering (0G-3M-22B ml/g )* plus 5 ml/g Liquid KaBloom I get to an N-P-K of N40-P186-K309 but my TDS is only 1100 TOTAL even with the added 325 TDS of my water. If I up the nutrient ratio to meet the extrapolated PPM, I'm going to end up bumping my N-P-K figures even higher, which I'm concerned about due to possible nutrient lockout. So is my math correct? I'm using this for my calculations PPM Calculator If my figures are correct which is the best way to go? Go with a lower TDS and supposedly correct profile or higher nutrient concentration, throwing the Mel Frank guide out the window?



*
Grow 2-1-6, Micro 5-0-1, Bloom 0-5-4, KaBloom 0-10-10
 

Snow Crash

Well-Known Member
Inevitably there is going to be a different measurement from what is listed on the bottle because they don't need to list everything on the bottle precisely.

I dunno about 1-1-2 ratio's and this Mel Frank character (wasn't he the voice of Bugs Bunny?). I hear that the rough guidelines for cannabis are more like 3-1-2 for veg and 1-3-2 for flowering.

Every media and method is going to require different levels. Specifically, coco requires reduced levels of potassium in the nutrient system because as the media breaks down it provides potassium on its own. Calcium and Magnesium play a crucial role in the whole system as well and I think they are often forgotten about. With the consideration that there are times when your plant needs as much, if not more, calcium as nitrogen I wonder why NPK doesn't include CaMg at the end of it.

Don't trust the calculators too closely, but they can definitely extrapolate percentages into projected elemental ppm's so your values are probably within 30% of actual. Unfortunately I don't use this system and I cannot do some measurements on my own meter for you. What I would do if I were you is imitate my peers and run what they suggest to run in the Formula's thread.
 

Neumann

Active Member
I hear that the rough guidelines for cannabis are more like 3-1-2 for veg and 1-3-2 for flowering

Every media and method is going to require different levels. Specifically, coco requires reduced levels of potassium in the nutrient system because as the media breaks down it provides potassium on its own. Calcium and Magnesium play a crucial role in the whole system as well and I think they are often forgotten about. With the consideration that there are times when your plant needs as much, if not more, calcium as nitrogen I wonder why NPK doesn't include CaMg at the end of it.

Don't trust the calculators too closely, but they can definitely extrapolate percentages into projected elemental ppm's so your values are probably within 30% of actual. Unfortunately I don't use this system and I cannot do some measurements on my own meter for you. What I would do if I were you is imitate my peers and run what they suggest to run in the Formula's thread.
Could you find citations on those? I can't seem to nail down anything other than the 1-1-2, that's why I used it.
I have no problems imitating my peers as long as I understand what I'm imitating and that the people I'm imitating understand it too. I don't mind following directions as long as I know they are right, not just easier.
 

Snow Crash

Well-Known Member
Just something I have seen time and again. Homebrewer is all about his DynaGro because they use that specific formula, and DynaGro is what all the university horticultural departments use. I'm sure if you did a little leg work you could find some more info on DynaGro in educational environments and the reasoning for it.

I've never seen 1-1-2 before.

When it comes to plant nutrition every strain, and every phenotype, is going to have particularities about them that require different levels. In a single garden you might have healthy plants from seed and sick plants from seed, which only goes to show just how important it is for harvest weight to be running something familiar to a grower if they are feeling the need to feed the plants.

Some might do better on a 3-4-5, Some might like a 7-5-5. Some might need a 2-2-5. And this doesn't take in to account variable needs of calcium and magnesium.

The concept I think you should be aiming for is following the Lucas/H3ad/Rez formula and what others who use the formula do. It is a formula for a reason and it is built upon the experience of many growers. I think you are trying to take the bottles from a single system and get them to do something they aren't really intended to do. Run true to the Lucas formula for a grow and the second time around you can then make changes based on what you see.

We're still young. Not like this is the last harvest you'll have. Get the feel for things before thinking you have any idea what to do. If you like the Lucas Formula then give it a shot and see what happens. There are a lot of nutrient systems, and nutrient ratios, and variable feeding schedules, etc, etc, and it is so easy to get lost in the mess of them. Keep a journal of the results and follow the system you're using before trying to make it "better" than it was designed to be.
 

Neumann

Active Member
I've never seen 1-1-2 before.

The concept I think you should be aiming for is following the Lucas/H3ad/Rez formula and what others who use the formula do. It is a formula for a reason and it is built upon the experience of many growers. I think you are trying to take the bottles from a single system and get them to do something they aren't really intended to do. Run true to the Lucas formula for a grow and the second time around you can then make changes based on what you see.
.
I think you are misreading my post. I know the Lucas Formula, I' m using it right now and that is where the 1-1-2 come from: http://www.angelfire.com/cantina/fourtwenty/articles/profiles.htm
"The nutrient profiles used during this project varied according to Mel Frank's recommendations for both moderate and strong light gardens. It was discovered that using 250ppm N during the growth stage produced no faster growth nor higher yields than using the 100ppm N found in his flowering profile (the one highlighted red in the For Flowering section below), and that the same flowering profile could also be used during the first two weeks of growth. It became apparent that using growth stage as a prerequisite for managing a cannabis crop's nutrient profile was not only overstated, but strengths and profiles were overstated as well. While this may not be the case with other hydroponically grown crops such as tomatoes, it does suggest that cannabis has simpler needs than many people and fertilizer manufactures advocate. In fact, using his 100N-100P-200K-60Mg flowering profile for all stages of growth with just three reservoir changes produced the same yields as twelve reservoir changes and stronger profiles did. Doing less and using less produced the same results as doing more and using more."
Further it says:
" Where the 100N-100P-200K-60Mg target profile relates to General Hydroponics Flora Series 3 part liquid fertilizer products, the same profile can be mixed without using any of the GH Grow component"
These are the nutrients I am working with.
". For expedience, that GH formula was rounded to 8M-16B-0G, which has become widely known in Internet cannabis circles as the Lucas formula."

So, I'm not trying to do something that the bottles aren't used for, I'm not trying to reinvent the wheel. I used the bottles exactly the way they were supposed to be used, got the results in N-P-K I expected but a lower TDS and that's my only question, is ratio more important than strength.
 
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