Best NPK Ratio for Veg and Flower

Discussion in 'Nutrients' started by Waiakeauka, Jul 31, 2011.


    Waiakeauka Well-Known Member

    There have been many people that say you need to use nutes that are designed for MJ, so what is the ideal NPK ratio for Veg and Flower? Many people say that you can use bloom booster that are high in Phosporus and other say you need more Potassium in flowering. What is ideal more Phosporus or more Potassium for flowering? Also what is the ideal amount of Nitrogen for flowering?

    scunkworm Active Member

    Ill try and answer all i know' with flowering the nitrogen needs to go down becasue if im right the plant/s get all the n they need for flowering, n in flowering feeds need to be low and thats only if you want to put n in as alot of grower's dont put n into flowering plants. with vegging the n must be higher then the p and k, apart from that ive woundered the same,
    obama8mychikin likes this.

    scunkworm Active Member

    Yeah i am right the plant gets pretty much gets all the n it needs in veg and thats y some dont use n in flowering plants,

    elduece Active Member

    Uncle Ben says to stick to something close to 2-1-3 ratio (i.e. 6-3-9 or 12-6-18 ) for veg and a 1-2-3 ratio (for example 3-6-9 or even 6-12-18 ) for flowering when adding nutes to soil. I would only use bloom boosters once or twice after the two week transition and that's it. I think it's pointless to use bloom booster at every feeding after the flower sites are established. Too much P will lock out N so it's advisable to just stay with real low numbers if you're not really sure.
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    homebrewer Well-Known Member

    Your info is pretty mixed up there. 3-1-2 for veg though I've found 1-1-1 works just as well. 1-3-2 for flower is by far the best NPK ratio I've tried thus far.

    Too much P locks out Zinc, Iron, and Copper. Not sure where you're getting N from.
    cannabis love

    cannabis love Well-Known Member

    I'm using Alaskan Fish Emulsion 5-1-1 for veg, and Botanicare 1-4-5 for flower.
    Skunkybud likes this.

    Rotweiller Well-Known Member

    Hello Waiakeauka. I'm not sure if this will help you or not but i found this on another website and it made sense to me -
    Cannabis requires a 1:2 ratio of P to K throughout all stages of it's growth.

    It's worth stating for the record the actual ratios of N, P and K that cannabis requires through it's life cycle:

    Vegetative Stage
    N - P - K
    3 - 1 - 2

    Flowering Stage
    N - P - K
    1 - 1 - 2

    Final Flowering Stage
    N - P - K
    0 - 1 - 2

    To translate this into a 12 week schedule for a typical Skunk type such as Cheese or Psychosis would give something along these lines:

    Veg week 1: 3 - 1 - 2
    Veg week 2: 3 - 1 - 2
    Flo week 1 : 3 - 1 - 2
    Flo week 2 : 3 - 1 - 2
    Flo week 3 : 1 - 1 - 2
    Flo week 4 : 1 - 1 - 2
    Flo week 5 : 1 - 1 - 2
    Flo week 6 : 1 - 1 - 2
    Flo week 7 : 0 - 1 - 2
    Flo week 8 : 0 - 1 - 2
    Flo week 9 : 0 - 0 - 0
    Flo week 10: 0 - 0 - 0

    This schedule reduces the Nitrogen two weeks into the 12/12 period which will assist in stopping the vertical growth (stretch). It cuts out all Nitrogen after 6 weeks which will result in a less leafy, smoother burning end product with greater density to the flowers. The last two weeks of plain water is sufficient to leach out all accumulated salts and give a clean end product. Three week flush as advocated by some really isn't necessary if the Nitrogen is cut out after 6 weeks. The people using a three week flush tend to use Canna nutes which have too much N in them for late flowering and this is why they get a benefit from flushing for three weeks.

    Hope that makes sense. Despite all the crap the nute companies fill our heads with about the need for all kinds of fancy bottles, you really don't need any of them. Cannabis is a simple plant, a weed in fact, and all it needs is the correct NPK at the correct time plus a full range of trace elements, that is hard fact and no amount of BS an marketing from the nute companies will ever change that fact.

    Anyway :-) Hope this helps you a little bit ? Good luck and Happy Growing :-)
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    uhavealighter? Active Member

    I back this statement up for sure! I have seen many experiments where people are trying to compare advanced nutrients to other nutes and this company has always clearly won. Mostly because their nutrients were developed from cannabis and not tomatoes. Maybe we should blend cheaper nutes to the AV's npk ratios? I believe it would be their n-p-k ratios over anything else. They do also have a lot of boron probably for some good reason.

    All of their nutrients schedules for the flowering stage, with additives or without, comes very close to 1-1-2-0.5 Ca-0.25 Mg. At the last two weeks, however, they have it closer to 2-3-4-1 Ca-0.6 Mg. And obviously a flush at the end.

    Advanced Nutes seems to have a lot of amino acids, humic acid, sugars, and microbes too.

    I also like that they don't have calcium mixed with phosphorous and magnesium in concentration.

    But I will stay away from them and mix up cheap, microbe friendly nutes using AV's ratio's.

    homebrewer Well-Known Member

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    Bynk Active Member

    What sources do you use for nutes to make up these ratios?

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    uhavealighter? Active Member

    For this grow you were very knowledgeable about dyna-gro and had no idea about advanced im guessing. second you only used connisuer and didn't get the full benefits of using at least a few of their highly recommended additives. Third your experiment didn't look very controlled. you compared nutrients using the same grow tray? Fourth you went into the experiment already thinking advanced nutrients sucked. Fifth your light is pretty damn far away from the plants. You might be able to pump up your nutes if you had more light going to your crop. the more light, more co2, the more nutes.

    To me this experiment was sort of biased. you claimed dyna-gro was better even though the experiment had not yet finished.

    Were you following the manufacturers feeding schedules or your own? It you were not I wouldn't technically call the experiment dyna-gro vs. advanced nutrients.

    I prolly hate advanced nutrients just as much as you do because they overcharge and overhype their products with ridiculous names, but one experiment with plants in 6" rockwool cubes isn't gonna cut it for me.

    Advanced is really 'Advanced'.

    This one of the good controlled experiments, but they guy went into it liking earth juice like you did dyna-gro. In this experiment he claimed dyna-gro was actually the worst of the 8 nutrient lines he tested. All the info is in one spot. I wish i could read your whole 80 page forum post,but that would prolly take a couple days.

    uhavealighter? Active Member

    im currently using pure blend pro grow and pure blend pro bloom, and liquid karma throughout flowering. Use just tap water. then i kick it was some hydroplex the last two weeks before I flush currently for extra phosphorus and potassium. I'm way too experimental to keep with the same nutes, but it really doesn't matter. you really just want something with a stable ph.

    homebrewer Well-Known Member

    Then check out this journal where I first tested DynaGro against a fertilizer brand that I had years of expereince with (GH):

    The idea was to show how good GH was, I was wrong, now I use DG.

    They're all the same salts and ratios are what is important. As for 'boosters', I used koolbloom to start but felt hydroplex was a better match for AN's 1-1-2 base nute ratio. If you don't understand that it's all about the salts then stop reading right here.

    All my tests are in that same tray at the same feeding levels (or whatever levels maintain healthy foliage) with fresh bulbs. I grow cloned strains that I've had for round after round and I know how to grow them.

    They do, and I was right.

    I could feed less than about anyone on this site and yield more than them. It's not about 'pumping up the nutes' or scorching leaves with an HPS that's too close. You've got some learning to do.

    AN doesn't know my environment or my strains better than I do. They are no different than any other company as they can only provide a general guideline to feeding which helps newbs get started. If you're blindly following labels then you've got some more learning to do.

    I'm not here to convince you of anything. I would actually appreciate it if you didn't use DG because people with your line of thinking grow ugly plants (stressed from over-feeding and lights that are too close ;) ).

    Do you really consider that a good comparison? Where are the pictures of him testing the products with weekly picture updates of growth?

    Here is a test that I have going at the moment, my own strains actually at day 21. I'd love to see some healthier plants from you ;):

    mr. green thumb 01

    mr. green thumb 01 New Member

    First of all I would just like to say sorry to homebrewer about getting started on the wrong foot a while back im sure you remember. And no hard feelings on my part. Forget and forgive my friend. I dont really even remember what it was about but its all good I just hope you feel the same way.

    Second I would like to say that I agree with your 1-3-2 ratio. All you people need to read books and not research internet post's. Read the Cannabible by Jason King it says specifically cannabis likes a 1-3-2 ratio for flower and a 1-1-1 ratio for veg. I would trust the books info before anyone on this site.

    I use to use GH flora nova and got great yields and quality but I didnt like how they it treated my roots in my DWC so I switched to BC but they have a 1-2-3 formula or something with a lot potassium. (I didnt even think of this before buying) They gave me good quality still but seemed to be a little denser but smaller flowers with less yield per plant on average. I can only attribute this to the low phosphorus in BC and high phosphorus in flora nova. I think the 1-2-3 ratio is best for REAL flowers where people really care about good strong stem development. But heck if the Cannabible says 1-3-2 ration id go with that. Im still looking for more credible info about this topic..I find it interesting you say uncle ben likes a 1-2-3 ratio and cannabible says 1-3-2 im gonna have to look more into this now...

    Bleedslikeavirgin Member

    How about NPK rations when producing seeds? Just like in the flowering phase until seeds are ripe for picking?
    Uncle Ben

    Uncle Ben Well-Known Member

    I find it interesting that some folks misquote me. If you want a guide, because you really haven't learned what makes a plant tick, then - Veg - 9-3-6. Bloom - 1-3-2, or do what I say, not what I do. I grow most of my pot using a high N food from start to finish - 18-4-9 slow release. There is way too much emphasis put on veg versus bloom foods. You should use whatever it takes to produce and retain the most amount of foliage from start to finish.

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    AmishMan53 Member

    major newbie question since i'm about to get into my first grow...

    I see some people use jacks classic 20-20-20.. i tend to presume by volume that 20% is nitrogen-same-same and the leftover 40% is random other stuff like calcium.

    then i see some people use 2-1-6 floragrow for veg and switch to something with equally small numbers. 2% vs 20% by volume sounds rediculous and i wonder how people don't burn MJ using jacks.

    I understand ratio's, but when i'm supposed to be feeding at "full strength" at week 4 or 5.. full strength could be overkill with jacks classic and underfeeding with flora-bloom (as this is flowering at this point).

    Since i don't have neither product on-hand, i don't already know that recommended dose of jacks is 1 tbsp to 1 gallon and flora-grow is 5 tbsp to 1 gallon at full strength late in growth(i may be way off, but is only example). If this is the case, then with a simple percentage given to start at i will be able to deduce how much of any fert to use during any period of MJ's growth. to explain, 3%N-1-2 would be full strength of floragrow at week 1 but if i'm using jacks classic, 3% would be 1/7th it's recommended dosage to start with.

    This product interested me since i've heard that MJ is an acid loving plant. I will want to stick with water soluble until a few grows and i'm ready to experiment, but this is something i will probably try when i know what i'm doing and can understand MJ's needs. Also, I do understand each strain is different, but a basic guide or starting point will be great.
    Uncle Ben

    Uncle Ben Well-Known Member

    Be damn careful regarding what you hear. You feed the plant based on its needs, not some chart. When it is barely bulking up, then it needs less salts like during early juvenile and late flowering. You don't ever give a plant 1 Tbsp. per gallon.

    Jack's 20-20-20 is fine from start to finish in soil. Get a handle on plant nutrition before growing. It sounds like you're going to do the noob thing and set yourself up for failure.

    puertorrican diesel likes this.

    AmishMan53 Member

    It was the same for lighting as well. I originally heard flourescent lighting would work, so i look at prices and decided on a T12. Then i read more into it and found out T5 is what i need... but then i realized it wouldn't suffice either because i wanted a 9 plant grow scrog.

    In the end, i settled on a 600w MH/HPS ballast for a 4plant grow, 2-4 weeks vegetation (at least until plant gets to 2 ft. tall, then switch to 12/12).

    In short, i know my ability to learn and i don't stick to just one answer (as i've heard it's different per grower situation). I found a page that tells what will happen to a plant if it becomes deficient in nitrogen, calcium, etc. I plan on keeping to that page so i can identify any situations i come across, as well as RIU if i'm unsure. I DON'T plan on giving my plants nute burn or root rot, the more extreme issues. Jacks 20-20-20 sounds perfect for me if i can go through the whole process with just it ("attempting" to keep my budget low). This being said, at 20-20-20 i feel i need somewhat of a feeding regimen so that i know i won't overdo it.

    To put it as simply as possible, as long as i keep getting responses to my inquirys like "that won't do" without further details, I WILL screw up. "That won't do" doesn't explain what WILL do. So far uncle ben, your post tells me this much - feeding a plant isn't like cooking food, the wrong measurements doesn't just make it taste bad, it can kill it. Hate to say, I don't use cookbooks nor sign up to cooking websites. However if i'm spending 300+ dollars on something (like growing MJ) then i'm gonna read read read so as to make sure i don't waste that money.

    So please, refer me to an easy to understand guide that will at least guarantee i don't overdo it. Simply saying flora gro works great and jacks classic works great, with all my other reading, tells me i'm missing something major.
    Uncle Ben

    Uncle Ben Well-Known Member

    This needs to be said first....for some strange reason folks need to make pot growing as complicated and confusing as they can. That's why you must empower yourself with solid botanical knowledge rather than take someone's advice on lighting, foods, defoliation tricks, etc.

    DO NOT start until you buy and read Mel Frank's "MJ Insiders Growers Guide". It will be your short cut to success.

    That is the most comprehensive, down to earth book on horticulture. Get your nose out of this blind-leading-the-blind forum and into Mel's book.

    Check out my Tweeks thread in Advanced and read my posts. You'll quickly find I don't subscribe to most principles or products pushed around here, only sound culture.

    Learn these concepts too - Chalker-Scott/Horticultural Myths_files/index.html

    Second group on the page - READ

    Yes, most is geared towards other plants like orchids, but it's the concepts you need to be looking into, they are solid and will translate over to cannabis culture. If you master these concepts, you can grow this weed. Treat cannabis like a tomato and you'll be successful. Treat it as it is - nothing more than a flowering tropical annual.

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