Are there any scientific consensus as to what the actual ideal NPK ratios are for cannabis?

HandyGringo

Well-Known Member
I've been looking around a bit and I keep running into various Youtube channels trying to advertise all those overpriced brand nutrients. I know those are a bit of a scam, so I was hoping to dumb down my fertilizing and buy something not meant for cannabis. Like, tomato fertilizer or general garden fertiliser, ideally something organic I can top dress.

But I realize, I'm not really sure what NPK to even go for. I know some people swear you can do your entire grow with FloraBloom, for instance, which is 6-17-15 or so. But then you look at other popular cannabis fertilizers and many have different ratios.

I watched a video by Dr Bruce Bugbee, talking about optimizing yields, and he said they used 20-10-20.

But reading various sites they say 3-1-2 or 3-1-1 or 1-3-2 etc.

Is there any sort of consensus?
 
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cage

Well-Known Member
Something like 3:1:2 for vegging,
1:1:2 early flower and then 1:2:4 is pretty good starting point.

Depends really on the growing method how much margin of error there is.
If you are slacking water changes in recirculating systems, you need to be pretty spot on what you feed.
But any kind of drain-to-waste or traditional pots with watering from top flushes the excess usually pretty well.

With organics you have the problem of slow solubility so you have harder time adjusting when they release.
But bone meals contain plenty of phosphorus and calcium and should be there on the list atleast,
Some compost, poo in general, chicken, cow, worm castings etc.
 

LewberDewber852

Well-Known Member
Different for every situation. There is no really one size fits all for every cultivar, and again situation. Up to their grow god (you) to determine what’s best for them in that particular situation.
Sorry was talking to a desk neighbor today on some deep shit and this seemed like the right response to your question. -People are here to help the plan(e)t.

I’m sure there is a general one size fits all with NPK in inert grows. But definitely not guaranteed to grow that dankness.
Although with “organic”, or should I say living soil, it’s not that simple.
 

Nizza

Well-Known Member
I do 3-1-2 on veg and 2-1-3 on flower for a basic guideline

However doing drain to waste I can get away with either because whatever the plant doesn't want will be washed out with the runoff water
 

f.r

Well-Known Member
In the end cannabis will grow well with a various mixes. Genetics will perform better with certain nutrient ratios, but in the end they all will perform well enough with a multitude of NPK ratios.

The only hard and fast rule imo is to not over do ammonical nitrogen
 

FatherNelson

Well-Known Member
In my opinion, it depends on consistency, build up, and how you allow your plant to adapt. Randomly bombing 1 special nutrient that its never had before will cause shock.

Analogy:
When I was young, I would eat 2 pieces of pizza. Now I can eat a large.

I dont drink milk very often. If I drink 3 glasses and a large pizza I get lactose intolerant and feel like Im dying for a couple days.
 

conor c

Well-Known Member
If you think about it they come from different continents and have a lot of mixes soo each strain probably has different needs.
Bingo pretty much this it depends what your growing some feed hard some barely want anything and will still claw up at the hint of N like some pure sativas and the like do i wouldnt say there is an ideal one size fits all for all cannabis
 

Beeswings

Well-Known Member
I've been looking around a bit and I keep running into various Youtube channels trying to advertise all those overpriced brand nutrients. I know those are a bit of a scam, so I was hoping to dumb down my fertilizing and buy something not meant for cannabis. Like, tomato fertilizer or general garden fertiliser, ideally something organic I can top dress.

But I realize, I'm not really sure what NPK to even go for. I know some people swear you can do your entire grow with FloraBloom, for instance, which is 6-17-15 or so. But then you look at other popular cannabis fertilizers and many have different ratios.

I watched a video by Dr Bruce Bugbee, talking about optimizing yields, and he said they used 20-10-20.

But reading various sites they say 3-1-2 or 3-1-1 or 1-3-2 etc.

Is there any sort of consensus?
Yeah the easiest way for you to succeed, in my opinion, would be to transplant into 5 gallons of Ocean Forest soil in 7 gallon pots, and just top dress with more Ocean Forest when needed for an indoor grow. For an outdoor grow just plant it in the ground pretty much anywhere, the roots and microbes will find what they need. I see 8 foot tall wild plants every fall that I know didn't get fed.
 

ShowMeDaBudz

Well-Known Member
3-1-2 is the most common ratio for garden veggie plants and works just fine for vegging weed too. Ive been running 1-2-2 after the stretch. Usually with 5-1-1 Fish juice and MorBloom 0-10-10. MEGACROP with minor adjustments works for all of it if you want simple.
 
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