Nutrient Ratios Information

KrAzY80

Active Member
I found this the other day while googling off a suppliers website. I thought it was interesting and very clear on nutrient ratios and correlations with each other. I would like to know what others think of it and see if you agree with the whole nutrient ratio approach or more towards the Lucas Formula by providing enough of each nutrient so its available at all times regardless.

Environment plays a very important role in plant growth upto a point. Once optimal environmental levels have been achieved in the hydroponics grow room, however, it is the quality of nutrition that determines crop quality and output. The following background information will be useful in understanding of the role of hydroponics nutrients

Nitrogen
Plants absorb nitrogen from fertilizers in both Nitrate (NO3) and ammonium (NH4) forms. Both ammonium and nitrate forms are available in the standard fertilizer mix supplied. It should be noted however, that ammonium levels should be significantly lower than nitrate levels with a safe level being 10 to 20 times nitrogen available in the Nitrate form vis-à-vis the Ammonium form.

Ammonium is readily available to plants and can build up to toxic levels in plant tissue if it is not assimilated for growth. Besides, the Nitrogen from Ammonium is difficult to leach away once it is in plant tissue. It is therefore important too ensure that ammonium content in the nutrients is carefully regulated.

Over supply of fertilizers with high levels of Ammonium nitrogen manifests as distorted and dark growth starting at the plant’s growing tip. The imbalance may also lead to symptoms of other nutrient deficiencies despite these nutrients being supplied in the correct amounts. This is because of the nutrient imbalance that is created. Higher nitrogen levels are required during vegetative/green growth phases. After proper rooting of cuttings, nitrogen levels can be increased from ¼ strength to full strength over 10 to 14 days. Over application of nitrogen causes delayed flower and fruit development. Nitrogen levels at the time of rooting of cuttings should be around 100 ppm and may be increased to +250 ppm for aggressive growth under optimal conditions. Light conditions can make a difference to the Nitrogen to Potassium ratio, which can be about 1:1 under higher light conditions, while under low light conditions it may be as high as 1:5.

Phosphorus
Plants require the phosphorus content of the nutrient mix to be high during the flowering/fruiting phase of their life cycle. At other times amounts between 15 to 30 ppm are quite adequate for most crops. Over supply of phosphorus will be harmful during these stages as it will lead to imbalances of iron and calcium and even zinc. Iron and zinc have an association with the greenness of plants, phosphorus levels should therefore be increased only with corresponding increases in levels of calcium, iron and zinc. Calcium levels should be maintained at 1.5:1 ratio with phosphorus. Most commercial calcium nutrient formulations include the right proportions of trace elements to cover flowering/fruiting requirements. Phosphorous levels may be increased to 250 ppm during the peak phase maintaining important ratios such as calcium and micro-nutrients.

Potassium
Potassium is required in root development and also for the ripening process of flowers, fruits, and seeds. Potassium levels can be increased during the flowering/fruiting phase to harvest a heavy, colorful and firm produce. High potassium levels in some crops help increase resistance foliar diseases such as powdery mildew.

Under low lighting growth conditions higher potassium to nitrogen ratios in the range of 3:1 helps healthy vegetative growth. Under brighter the same nutrient proportion may be closer to 1:1 to stimulate vigorous green growth. Most plants do well on potassium levels in the range of 100 to +400 ppm.

Calcium
Calcium is an important component of the cell walls of plants and is also plays an important role in the processes of cell division. It requires to be maintained in a ratio to phosphorus and is best applied in greater amounts 1.5X the level of potassium. The calcium magnesium ratio is also important and should be maintained at 3:1. For instance with 150 ppm calcium levels in a nutrient solution, magnesium levels should be maintained at around 50 ppm.

Magnesium
Magnesium is associated with keeping the plant “green” and is a carrier molecule for certain plant processes. Indoor crops will generally benefit from elevated magnesium levels. Reports on the use of elevated levels of Magnesium have been positive with growers harvesting firmer flowers and fruits.Hydroponics calcium formulations often contain additional amounts of magnesium. It should be noted however, that magnesium levels should be maintained around 1:3 ratio to calcium.

Other Nutrients
In addition to the above nutrients, that constitute the main macro-nutrients that plants need to obtain from the nutrient formulations, there are other macro and micro-nutrients that are vital to various plant processes. While plants use macro-nutrients in large or appreciable quantities, the micro-nutrients are required in trace amounts Plants absorb carbon, hydrogen and oxygen from the air and water. The following table lists various nutrients essential for plant nutrition and the different plant processes they serve.

Macronutrients
Carbon--> Organic compounds formation
Oxygen--> Energy release
Hydrogen--> Water formation
Nitrogen--> Chlorophyll, Proteins formation
Phosphorus--> Photosynthesis
Potassium--> Enzyme activity, starch formation, sugar formation
Calcium--> Cell growth, component of cell wall
Magnesium--> Enzyme activation
Sulfur--> Amino acids and proteins formation
Micronutrients
Boron--> Reproduction
Chlorine--> Root growth
Copper--> Enzyme activation
Iron--> Photosynthesis
Manganese--> Enzyme activation
Sodium--> Water movement
Zinc--> Enzymes and auxins component
Molybdenum--> Nitrogen Fixation
Nickel--> Nitrogen Liberation
Cobalt--> Nitrogen Fixation
Silicon--> Cell wall toughening
 

KrAzY80

Active Member
The one thing out of that I have never heard was the ratio between calcium and phosphorous. I always thought nitrogen and calcium were supposed to be 1-1. Does the p ratio apply during flowering as well?
 

Yesdog

Well-Known Member
Ermmm no responses? This is good stuff! Wanting to know tons more about the nutrient ratios against each other and what it means to the plant
 

HydroLynx

Well-Known Member
We need more threads like this. In-fact some scientifically researched papers on optimal nutrients ppm's for nft and media and for each stage of growth of our fav lil plant would make me drool.
 
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Skybound420

Well-Known Member
I'll claim the other end of 2018 I guess. I been shaking the bullshit out of this tree, but still waiting for the good fruit to fall. So far just crab apples and leaves. Here's some of my notes to maybe reinvigorate the chatter.

Ranges and Targets.JPG

and some comparisons. I've only ever used GH until switching to Jack's 321, and that I only tried for about a month before collecting quite a few various salts to make 9 bottles of concentrate. This gives me a shit load of options for tweaking N-P-K-Ca-Mg-S-Fe and Si. I'm seeing awesome results with my targets, but I suspect that Ca is still low and was hoping to find an answer of Ca is to relate to N in ratio. Ca being related to P is new to me as well.

Example Charts.JPG
 

HydroLynx

Well-Known Member
I'm running DWC, and I found those numbers are very hot. A few days ago I switched my bloom res down to N-P-K-Ca-Mg-S = 50-42-81-50-28-38. Still keeping P high but basically took a small fraction of the other numbers just to get my ec down.
 

Skybound420

Well-Known Member
I'm running DWC, and I found those numbers are very hot. A few days ago I switched my bloom res down to N-P-K-Ca-Mg-S = 50-42-81-50-28-38. Still keeping P high but basically took a small fraction of the other numbers just to get my ec down.
Which numbers did you find to be hot? Also, what does your micro ratios look like?
 

HydroLynx

Well-Known Member
I started with a high P Hoagland solution at about 50% ec, then went down to N-P-K-Ca-Mg-S = 100:50:150:100:95:44:69 was fine for one strain in winter, but now another strain in summer here leaves burnt and 'praying leaf' turgur dropped

Micros for both stock solutions were:
Fe EDTA = 3ppm,
Mn sulfate = 1ppm,
B acid = 0.3ppm,
ZnSO4 = 0.1ppm,
CuSO4 = 0.05.

Am looking at chelates for micros.
 

Skybound420

Well-Known Member
I started with a high P Hoagland solution at about 50% ec, then went down to N-P-K-Ca-Mg-S = 100:50:150:100:95:44:69 was fine for one strain in winter, but now another strain in summer here leaves burnt and 'praying leaf' turgur dropped

Micros for both stock solutions were:
Fe EDTA = 3ppm,
Mn sulfate = 1ppm,
B acid = 0.3ppm,
ZnSO4 = 0.1ppm,
CuSO4 = 0.05.

Am looking at chelates for micros.
Ya got pics of the damage? 50P isn't all that high. Some of the popular liquid lines are up around 100. I'm currently at 65, though i am in rockwool cubes potted, whereas DWC is the most difficult to manage. Are you certain that all other aspects of your grow are near ideal?
 

HydroLynx

Well-Known Member
No pics, maybe when lights come on i can take, but relly is typical upper leaf rust caused by calcium lockout I rate. I can use more extraction, app transpiration helps draw Calcium into the leaves. Plants are bit cramped, unfamiliar sativa strain. Was running 100:50:150 NPK on my last batch, just had purple leaves as it was winter I rate. But the bud wasn't terpy at all, some organic friends who grew the strain as well were impressed, I wasn't tho. DWC for me is simple, safe for experimenting with new hydro fert mixes. I want that electric lemon zam I used to get with GHE and DWC in my youth lol
 

Skybound420

Well-Known Member
IDK the level of truth, but I've read that potassium sulfate will enhance the lemon scents whereas mag sulf will enhance a fruity sweeter smell. In my final week I use both, but Hydro Buddy hardly calls for the use of any pot sulf all throughout the grow and mostly sticks with mag sulf. I'm doing a Triple Cheese (UK cheese x blue cheese) that smells like 80% pineapple juice with a minor tinge of palm sweat, and that's mostly all mag sulf fed.

I'm also chasing out the same rust spots which has me scouring the web for more info. I read an interesting article yesterday about the relation of Ca to B and how they influence each other's uptake, yet are somehow each only available in the opposing ph range of the other.

https://www.commercial-hydroponic-farming.com/nutrient-interactions-calcium-and-boron-ratio/
 

HydroLynx

Well-Known Member
Yeah heard that too. Would love to see the science behind those nutrients causing smells.

I actually use my own equations for my nutrients mixes, should get them checked out by others.

Good read thanx
 

Skybound420

Well-Known Member
Yeah heard that too. Would love to see the science behind those nutrients causing smells.

I actually use my own equations for my nutrients mixes, should get them checked out by others.

Good read thanx
If you don't know how to use Hydro Buddy, I made a tutorial on 420 about it. Then you can audit your own mixes. I started with Jacks, Calnit and Epsom like everyone else, but when I learned how to use Hydro Buddy, I realized how far away that was from desired targets. I can now hit my targets spot on with the exception of micros, and in the future I plan to make my own micro mix to hit every target.

https://www.420magazine.com/community/threads/making-your-own-nutrient-concentrates.455187/
 

HydroLynx

Well-Known Member
Yeah thanx maybe one day :)

Here's how I balance. 1mM means 1 milli molar unit ie 1 milli molar mass. Bit like a rubix cube puzzle, and I trust my own creative problem solving abilities over a "best fit algorithm". Let's think in terms of molarity first ie 1 milli molar mass unit per litre of water final volume:

For veg:
Key:

1 x [bottle A with balanced ingredients]
1 x [bottle B with balanced ingredients]

1
x [0.4mM CAN + 1mM Mg(NO3)2 + 1micros + 0.5HNO3]

1
x [1mM KH2PO4+ 0.8mM K2SO4 + 0.5mM MgSO4+ 0.2mM H3PO4]


1mM unit = given molar mass = mg/l = ppm
(god I love the metric sytem)


So the ppm's for each nute from the formulas above in brackets [] give:

NH4= 5.6mg/l ie 5.6ppm

NO3= 61.6+ 28+ 7 = 96.6 = 102ppm totN(5.6%NH4/Ntot)

P = 31 + 6.2 =37ppm

K = 39+ 62.4= 101


Ca = 80 + 15w = 95 (w = added ppm from tap water in res)

Mg = 24+ 12+ 1.5w =38

S = 25.6 + 16 + 6.4w = 48

And that's how I get my targets, takes some playing around tho...

 
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HydroLynx

Well-Known Member
Here's how I compute the fert salts i need for my stock solutions. Note I just use dosage rate instead of bothering with tank size and other nuisance factors. Also note I use 1 mathematical model instead of several separate and smaller steps, where I just plug in the various numbers for the nutrient salts and desired ppm's. Deriving this model will take pages of explanation.

Smg = mmol * M *Tvl / Dml/l (WhereTvlitres= 1l and Dml/l = 2.5ml/l)

Smg = Stock mass, ie mass of fertiliser salt added to the stock.

mmol =mmols of molecules for a given salt, ie intended (mili) molarity, per 1l finalnutrient solution.

M =Molar mass of that fertiliser salt.

Tvl= Total volume in litres of stock, ie the fertiliser stock solution’s final volume size.

Dml per l= Dosage rate in ml’s of fertiliser stock, per 1l final nutrient solution.


Here's how I calculate the needed salt mass for my stock solution for each nutrient, here is Magnesium Nitrate. So i just plug the numbers in for each salt and compute from this model.

Mg(NO3)2.6H2O:

Smg = 0.75mmol * 256.41 * 2l / 10ml/l = 118g


CAN (Calcium ammonium nitrate)


Smg = 0.5mmol * 1080.64 * 2l / 10ml/l =108.06g

 

Skybound420

Well-Known Member
All of that terminology is new to me. I just learned how to use Hydro Buddy a few months back after not knowing how to use it for years. I also recently began mixing my own nutes after bumping heads with GH 3 part for years. But reading through the math, I can't help but wonder the purpose of naming something mM, only to later name it mg/l? Also, in your math, I didn't see the reduction factors for P and K. Does your input numbers account for solubility of those?

Edit - (from my notes)
You can figure the ACTUAL amount of P by multiplying the label# by 0.44 and the K amount by 0.83
 

HydroLynx

Well-Known Member
Because it strated out as milli-Moles because we work with a salt say MgSO4 to get our targets... we balance the chemical formula using moles, and then convert moles into mg and into ppm. Like the molar mass for 1 milli-Mole Mg is 24mg. And the per litre bit assumed, ie 1mg per litre of water gives 1ppm. Quite simple.

Reduction for factors as in accounting for P205 and K20 you mean? Im using P as P which has a molar mass of 31, not the P205 nonsence, that's only needed if you backward engineer a formula given in terms of P2O5. Im solving this like a modern chemist would. I take MKP, and I see it has 1 mol of P and 1 mol of K, I look up the molar masses for them and boom those become my ppms due to my (fact-checked) assumptions above.

Yes well spotted. I have to make sure that the salt mass I computed does not exceed the stock volume size's solubility tolerance, the figures I looked up online and tablulated. MKP and K2SO4 and Boric acid are the salts I used that i must watch out for here

Also I use a slightly diff formula for the acids and micronutrients, acids come in liquid form, and the micronutes are treated differently because I already have ppm values that i looked up
 
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