[headband 707]

Originally Posted by spurr

I am looking forward to what you find. You seem to have a very good grasp of this matter, and you and I agree 100%: let the plant take what is wants, don't overfeed

I wrote a long and very well referenced thread elsewhere a while ago about cannabis tissue assays for nutrients and why less P is needed than is most often used, etc. I could post up some info in a different thread someday if your interested.

I'm not actually sure what you guys are talking about all plants can only take what they can take no more no less. Most ppl over do it with fertilizers and the plant will simply disguard the excess so it's a total waste indoors. peace out Headband707

[Dopeboy668]

Im a firm believer in less is more. I always start at quarter the recommended dose ferts and finish at a lil over half the bottle recommended dose. I think alot of people feeding at full strength are throwin money away.

[headband 707]

Originally Posted by Dopeboy668

Im a firm believer in less is more. I always start at quarter the recommended dose ferts and finish at a lil over half the bottle recommended dose. I think alot of people feeding at full strength are throwin money away.

Truer words were never spoken lol.. All manufacters will try to sell you ferts at optimal conditions but for most if not all indoor conditions, indoors don't have these conditions and plants don't need and will not take this much fert.A plant can only take what it needs no more no less the rest will just end up in your soil to be flushed away with the next watering. A real waste of cash..You will know if you have given your plant too many ferts if the tips are black.Less is more and look into things like seaweed , and various trace elements because ferts aren't the only game in town lol peace out Headband707

[Weird]

look at the plethora of aminos on advanced nutrients booster products and sweet products and youll start to see why they are so "advanced"


quarter strength was what I was taught when reagan was in office

Of course they do and always have. Organic takes it much farther.... There is a reason you can have rich organic amended soil with PLENTY of N left in it at the end of flower, yet the plant won't take any of it up because it knows when it's lifespan is over. It's an annual.

Another reason bottled fertilizers give such high doses is to A: get you to buy more.. B: are used on outdoor plants which can take WAY more fertilizer because they get pure sunlight.

Pretty sure that is why people cut the doses down so much, the less light available, the less food is needed by the plant. (in basic terms)

[headband 707]

Originally Posted by staff11

Of course they do and always have. Organic takes it much farther.... There is a reason you can have rich organic amended soil with PLENTY of N left in it at the end of flower, yet the plant won't take any of it up because it knows when it's lifespan is over. It's an annual.

AGREED!!!!! lol .. she just lets it sit there and it just flushes away with my greed LOL LOL

[ganjaments]

Originally Posted by headband 707

all plants can only take what they can take no more no less. Most ppl over do it with fertilizers and the plant will simply disguard the excess so it's a total waste indoors. peace out Headband707

Does this mean nutrient toxicity is a myth?

[spurr]

Originally Posted by Greyskull

found it!!!!



from Canna's webpage: https://www.cannagardening.com/node/1568?page=0,5

its an "info paper" on their coco product line. unfortunately it doesnt go into detail as to HOW/WHY it works... only that thats whats going on.

discuss....

Hey,

CEC has nothing to due with plant ability to self-regulate uptake of ions. CEC is really only a concern in media with high bulk density, and in media like coco or peat CEC is a non-issue. This relates to the quote/paper Carl posted above. If one was to increase the bulk density of coco or s.peat (via. heavy compaction or adding dense organic matter like compost) then the CEC would not be a non-issue.

The cations held in CEC sites can be freed via. acidic exudates from roots (ex. acidic H+ protons) and microbes, it can also be freed from interaction with other cations, and pH of soil solution.

The soil solution generally hold cations in equilibrium to cations held in CEC sites (usually once most CEC sites are filled).

Lots of people and companies that sell coco make claims about how great the CEC is, and how CEC of coco affects Ca availability to roots, neither of those claims are true to the degree the claims makers attest (again, see the paper Carl provided). S.peat has greater CEC than coco and peat doesn't have issues with Ca availability to roots...

If there really is an issue with Ca availability to roots in coco (which I have never noticed) than the issue is not due to CEC, it could be due to poorly flushed coco holding higher levels of P, K and S ions, which could affect availability of Ca ions. I for one do not believe there is a Ca 'issue' with coco.

The whole topic of CEC and AEC is misunderstood by companies selling products (like coco) that are thought of to have high CEC. For example, CEC of most humus/clay rich soil is around 5-20+ meq/100g, and coco as CEC around 40-60+ meq/100g and s.peat has CEC around 60-80+ meq/100g. Of all those media, it's only the soil that a grower needs to be concerned about in terms of CEC. Or coco or s.peat with intentionally increased bulk density.

The CEC fo coco is not only lower than s.peat, but the bulk density of coco is less than s.peat too! Thus, the CEC of coco is a non-issue, and any company who claims otherwise needs to study up...

Canna is full hot air on this issue of CEC and coco...

[spurr]

Originally Posted by Zen Master

can you put this in doodoo dumb language?

what I'm getting is

"no matter what you feed it, the plant is only gonna take what it wants, not what you force down its gullet"

Yup, except for ammoniacal N, and unless the osmotic factor is so high (ex. very high EC) that it overrides plant self-regulation of ions like nitrates, P, Ca, Mg, etc.

Basically we should try to provide sufficient level of ions, and let the plant take what it needs depending upon it's growth stage. Let the plant be the 'boss'.

Another point on this topic is the false idea that we need 'veg' and 'bloom' ferts. All we need is one fert and use it all the time, this is how the Lucas formula is used. When I used to use the Lucas formula that is how I used it too, for many years. The plant will take what it needs when it needs it; if it takes in more than it needs it will store it in tissue for later use (esp. in terms of partially-mobile and fully mobile elements within plant tissue). Also false is the idea that we need to, and should, boost P during pre-flowing and flowing.

The topic of why plants need much less P than most cannabis growers think is not really relevant to this thread, but suffice it to say over 50 ppm of soluble (i.e. plant bio-available) phosphate anions is unneeded and can hinder stalky plant growth. To keep phosphate anion soluble it's wise to include citric acid in your fertigation water. Ex. Fe cations will make phosphate anions insoluble; but if citric acid chelates the anions first the Fe won't make them insoluble--thus the anions won't precipitate out of solution and no longer be plant available. The greater the P (and N) the greater the plant will stretch and the greater the internodal length, esp. important for pre-flowing when people tend to boost P with bloom boosters. During pre-flowing is a time when it's best to NOT boost P, but boosting K is fine because it has little effect upon internodal length/stretch and can increase yields. IMO the efficacy of bloom boosters comes from the K, not the P.

Here is what I feed when using chems, I use this all the time for vet to harvest. There is no need to use grow and bloom ferts, as has been shown for a long time by those using the Lucas formula:

Spurr wrote:

Below is my best effort to make an ideal chem fert mix using General Hydroponics Flora series to provide cannabis with sufficient level of elements. Ideally I would drop N to around 100 ppm so using maybe 3-4 ml of GH Micro and using 2.5 ml of CalMag+ might be better but I haven't done the math for that yet. The following mix is what I have been recently testing with ACT to see how it effects the microbes; no data to report as I haven't done enough testing yet. I have tested the following mix for growing cannabis without organics and it preformed better than the Lucas formula without excess ions found in the Lucas formula (which is based upon flawed claims by Ed Rosenthall, Mel Frank, George Cervantes, et al.):

My test mix with GH Grow/Micro/Bloom at 5/5/5 ml with CalMag+ at 5 ml and ProTeKt at 2.5 ml (all per gallon; along with citric acid to keep P anions soluble):

• Total N...140 ppm
• Nitrate N...130 ppm
• Ammonicial N...10 ppm
• P.....39 ppm
• K.....155 ppm
• Ca...126 ppm
• Mg...46 ppm
• S.....15 ppm
• Fe....3.1 ppm
• Mn...0.8 ppm
• Si.....56 ppm
• total PPM = 580
• Ca:Mg ratio = 2.7
• Nitrate N:Ammonicial N ratio = 13

FWIW, here is data from CNS17 (from bontaicre) thanks to Carl Carlson:

Carl wrote:

15 ml per gallon

• Total N - 137 ppm
• Nitrate N - 131 ppm
• Ammoniacal N - 6 ppm
• P - 40 ppm
• K - 152 ppm
• Ca - 128 ppm
• Mg - 23 ppm
• S - 50 ppm
• Mn - .22 ppm
• Mo - .02 ppm

[spurr]

ganjaments wrote:

Does this mean nutrient toxicity is a myth?

No, plants can't self-regulate uptake of ammoniacal N (like ammonia and ammonium) and it becomes phytotoxic to roots (burns them) when the plant is not able to move enough sugar (from photosynthesis) into the roots to convert the ammoniacal N into plant usable forms. When there is a lack of sugar, or the uptake of ammoniacal N outpaces movement of sugar into roots, phytotoxicity sets in.

Ammoniacal N is what causes nutrient toxicity from N, not nitrates AFAIK. In terms of P, the plant can self-regulate uptake of phosphate anions and excess gets converted (at least most of it) and stored in plant tissue.

Plants can self-regulate uptake of (at least) nitrates, P, Ca, Mg, and probably K, but not ammoniacal N (e.g. ammonia and ammonium).

The plant will take what it needs when it needs it; if it takes in more than it needs it will store it in tissue for later use (esp. in terms of partially-mobile and fully mobile elements within plant tissue). Plant self-regulation of ion uptake doesn't mean the plant stops taking in 100% of said ions, but it can/does reduce uptake to small or great degrees.

FWIW, if ammonium and nitrate is co-applied the plant will take up the ammonium faster and use it faster. For the first few hours (ex. in a fresh hydro rez) the ammonium will increase uptake of nitrates, but then after a few hours ammonium will decrease uptake of nitrates by the plant. I assume this is because the ammonium is converted into amino acids and moved into the phloem, that in turn signals the plant to reduce uptake of N (as nitrates).