The Myth of Low N

[1971]

if you are referring to me... hardly. just a guy wanting to know why people decided on the formula they did, to understand more of the science of it, etc.

so with you running such a high N in your recirc formula, especially compared to others, i guess i am just trying to understand.

any help is appreciated

 

[thefatman]

well, for example, is the bloom recirc formula i found:
Nitrogen 293
Phosphorus 80
Potassium 350
Magnesium 91
Calcium 268

now when i put this into hydrobuddy, it gives me a much too high EC. so if initially i mixed it to 100 gallons, i can dilute in half again to arrive at an EC i am more comfortable with. after halving again, would the ppm's then be half of what they were originally? i know, i'm retarded for even asking

Yes they would be halved again.

beyond those questions, and excuse me for being a bit tired, i am curious as to the reasoning behind the high N and Ca ppm's. your formula gets thrown around quite a bit but not the reasoning for picking those numbers. not because i am trying to debate them, but because i'd like to learn more

The high nitrogen is due to mj being a large consumer of nitrogen through both the veg and bloom state although some strains prefer a bit lighter Nitrogen during the last half or 1/3 of bloom then do most strains.

IMHO the need for calcium ppm as high or near as high as the nitrogen ppm is less necessary as the proportion of hair roots increase due to growing with a very well circulated DWC systems or with HP aero or air atomized aero where short spray times are used to greatly increase the amount of hair roots.

 

[thefatman]

if you are referring to me... hardly. just a guy wanting to know why people decided on the formula they did, to understand more of the science of it, etc.

so with you running such a high N in your recirc formula, especially compared to others, i guess i am just trying to understand.

any help is appreciated

I was referring to Spurr as being another fertilizer formulator/mixer. They are definitely a quite small minority of growers.

 

[1971]

i figured after i posted that

did you come to these conclusions via plant analysis?

so in a recirc system the Ca could be dropped throughout flowering? if that is the case, would i keep it on par with my N as it is dropped?

 

[thefatman]

Mainly through observation but it appears to be backed up by tissue analysis but it is really hard to be sure as the number of grows I have done with a high ratio of hair roots is small in comparison to those grows without a large ratio of hair roots. One also needs to also consider that the roots system of plants grown from seed responds some what differently than clones to growing methods geared toward producing a large number of hair roots.

It is not dependent on whether it is a recirculating system but it is instead more dependent on the ratio of hair roots to other roots. With most grows it seems that the ratio of nitrogen to calcium should be around 1.0 or 1.3. The ratio during budding should be reflect a higher amount of calcium as the nitrogen drops in most recirculating systems i.e. again it means considering the amount of hair roots present. If their is a large amount of hair roots the amount of calcium will be decreased along with the amount of nitrogen near the end of the bloom cycle.

 

[turbolaser4528]

I like a 3:1 Ca to Mg

Spurr is on to something with all this..

I hope you make a great one-part nutrient with everything cannabis needs to reach its genetic potential, I'd definitely buy it.

 

[thefatman]

I like a 3:1 Ca to Mg

Spurr is on to something with all this..

I hope you make a great one-part nutrient with everything cannabis needs to reach its genetic potential, I'd definitely buy it.

I thought we were on the Nitrogen/Phosphorus/Potash issue.

For what it is worth I see nothing wrong with the 3:1 Ca:Mg ratio, however I run closer to a 2.0 or 2.25 to 1 ratio. I do use a lower N:Ca ratio then Spurr as I grow with a method that produces an extreme amount of hair roots so I need not use as much Calcium as used in methods such as standard Hydro/DWC/Coco.

fatman's Bloom DTW without Ammonium Nitrate

ppm
Nitrogen 400
Phosphorus 100
Potassium 449
Magnesium 70
Calcium 100
Sulfur 134
Iron 10.00
Manganese 5.00
Boron 5.00
Zinc 5.00
Copper 1.00
Molybdenum .09

Part A (Ounces)

Calcium Nitrate 8.0
Potassium Nitrate 6.7
Magnesium Nitrate 0.92
Iron Chelate 1.63

Part B (Ounces)

Potassium Nitrate 6.7
MonoPotassium Phosphate 7.6
Ammonium Sulfate 7.36
Manganese Sulfate 0.324
Boric Acid / Solubor 0.442
Zinc Sulfate 0.351
Copper Sulfate 0.071
Ammonium Molybdate 0.003

Volume of Stock Solutions 1 Gallon
Dilution Rate 100 Gallons

I normally dilute to around 1 gallon to 300 gallons

 

[1971]

it is really interesting to read this stuff...thank you guys for sharing!

 

[Coco_nuts]

Interesting stuff.

Ok so i have been using h3ad rezipe (GH 6/9) in coco, usually i cut out the micro for the last 4 weeks of flower.

I am at 30 days flowering today so i havnt cut the micro, if you guys want you can advise me on how to continue and i can post the results.

To be specific i have been feeding them 5/7.5 because i noticed the leaves looking very dark with some canooing and the leaf tips curling down slightly.

Also what is Spurrs GH recipe? I assume its not specifically for coco?

 

[1971]

i think the biggest issue is finding a NPK ratio you like. mixing via direct addition makes it an easy process

 

[thefatman]

Interesting stuff.

Ok so i have been using h3ad rezipe (GH 6/9) in coco, usually i cut out the micro for the last 4 weeks of flower.

I am at 30 days flowering today so i havnt cut the micro, if you guys want you can advise me on how to continue and i can post the results.

To be specific i have been feeding them 5/7.5 because i noticed the leaves looking very dark with some canooing and the leaf tips curling down slightly.

Also what is Spurrs GH recipe? I assume its not specifically for coco?

I would not recommend cutting the micro through out the bloom stage. I personally do not know anyone cutting micro nutrients during bloom. Actually I know many people who add additional iron through out bloom while still using normal levels of all micros nutrients.

 

[Coco_nuts]

Hey fatman

Thats how its done with the h3ad rezipe:

https://www.icmag.com/ic/showthread.php?t=55683

 

[thefatman]

Hey fatman

Thats how its done with the h3ad rezipe:

https://www.icmag.com/ic/showthread.php?t=55683

That is a Coco thread where the thread originator IMHO under waters his Coco medium. As micro nutrients are only taken up in trace amounts it only stands to reason if very little excess water is applied to the Coco media that an excess of micro nutrients would accumulate in the Coco media. I would not recommend that a person water their Coco media so little that very little water drains from the media. Why would one want to deal with locked up nutrients due to never flushing or by applying so little water to the media. It is well known that most Coco has a CEC potential and also that some nutrients are more prone to leaching than others so why encourage problems through under watering.

No I did not read the whole thread as it interested me very little as I quit using absorbent medias a long time ago do to CEC and absorption problems that inert non absorbent medias do not have.

I now use no medias so I use chemical micro nutrients through out the grow except during initial rooting of clones.

 

[Coco_nuts]

I normally have a 10% runoff.

 

[desertsquirrel]

That is a Coco thread where the thread originator IMHO under waters his Coco medium. As micro nutrients are only taken up in trace amounts it only stands to reason if very little excess water is applied to the Coco media that an excess of micro nutrients would accumulate in the Coco media. I would not recommend that a person water their Coco media so little that very little water drains from the media. Why would one want to deal with locked up nutrients due to never flushing or by applying so little water to the media. It is well known that most Coco has a CEC potential and also that some nutrients are more prone to leaching than others so why encourage problems through under watering.

No I did not read the whole thread as it interested me very little as I quit using absorbent medias a long time ago do to CEC and absorption problems that inert non absorbent medias do not have.

I now use no medias so I use chemical micro nutrients through out the grow except during initial rooting of clones.

Fatman, as usual i disagree with nearly everything you posted, as well as find it totally off topic.

First of all the watering practices you are recommending are excessive and lead to compaction of the media, waste, and poor O2 availability; all of which contribute to significantly reduced osmosis, growth rate, and flower yield/quality.

My coco is watered from the bottom up (filling coasters under each pot.) Not only does this process decrease compaction, eliminate waste, and promote osmosis, it allows water to be applied in the appropriate amounts, never coming close to field capacity, which your recommendations imply to surpass.

Rather than blame under watering for nutrient lock up i would look to the unscientific approach you take to the actual available profiles of the application mix you are using, (as you pointed out in "the myth, of the high p myth.") I am sure that that lack of attention creates much more variance in the media profile then "under watering." If, in fact, "under watering" contributes to an imbalance at all.

All of our warehouses reuse our co-co (never is it wasted) and thus if it were ill managed in some way would be readily apparent. In fact the opposite is the case. With each reuse the co-co gets better and better.

Here is one example of our warehouses that use both coco and Hydro on site. both media receive the same nutrient applications btw.

https://www.icmag.com/ic/showthread.php?t=215910

If you would like to see more there are 20-30 of my threads on the farm you can check out, and a few examples below.

Fatman how come you do not post any pictures of your work? At any rate i would be happy to move to a coco or micronutrient thread to discuss this further because it simply has nothing to do with nitrogen, the subject of this thread.

 

[desertsquirrel]

It is not dependent on whether it is a recirculating system but it is instead more dependent on the ratio of hair roots to other roots. With most grows it seems that the ratio of nitrogen to calcium should be around 1.0 or 1.3. The ratio during budding should be reflect a higher amount of calcium as the nitrogen drops in most recirculating systems i.e. again it means considering the amount of hair roots present. If their is a large amount of hair roots the amount of calcium will be decreased along with the amount of nitrogen near the end of the bloom cycle.

how do you know what your ratios are?

I have never bothered to calculate just what I supply of each nutrient after dilution.

Do you have any data or pictures involving your "root hair" (do you mean hyphae?) to N uptake ratios? Are you using a microscope or a lab for a count/measurement? any system even rockwol can be quite rampant with them also, so why would it even be relevent? Here is an example:

https://www.icmag.com/ic/showthread.php?t=215941

Or pics of the HP aero system you seem to mention in every post?

 

[Coco_nuts]

Desert squirrel i have been looking at the bottom feeding "autopot" system, dont know if you know it. It looks very promising, its gravity fed so no electricity.

Dont think it applies to you but i was wondering what you think of it as i want to upgrade.

What ive garnered from this thread is that i should maintain 140ppm N right until the end of flowering, so instead of cutting out the GH Micro i should use 4-5ml per 5litre? (100 - 130ppm N)

 

[grapeman]

Soil food web, N and increased CO2.

http://www.plosone.org/article/info...PlantBiology+(PLoS+ONE+Alerts:+Plant+Biology)

 

[dgr]

My coco is watered from the bottom up (filling coasters under each pot.) Not only does this process decrease compaction, eliminate waste, and promote osmosis, it allows water to be applied in the appropriate amounts, never coming close to field capacity, which your recommendations imply to surpass.

...

All of our warehouses reuse our co-co (never is it wasted) and thus if it were ill managed in some way would be readily apparent. In fact the opposite is the case. With each reuse the co-co gets better and better.

Here is one example of our warehouses that use both coco and Hydro on site. both media receive the same nutrient applications btw.

https://www.icmag.com/ic/showthread.php?t=215910

desertsquirrel,
I took a glance through your posts and couldn't find an answer to this. When bottom watering coco, how often do you flush the media for salt build up? I am dealing with what I believe to be nitrogen toxicity issues in ebb and flow coco. I decided to flush some plants and checked the runoff. My truncheon meter read over maximum EC for it's scale >3.6 EC I believe.

 

[thefatman]

Fatman, as usual i disagree with nearly everything you posted, as well as find it totally off topic.

First of all the watering practices you are recommending are excessive and lead to compaction of the media, waste, and poor O2 availability; all of which contribute to significantly reduced osmosis, growth rate, and flower yield/quality.

What watering practices did I recommend? None.

My coco is watered from the bottom up (filling coasters under each pot.) Not only does this process decrease compaction, eliminate waste, and promote osmosis, it allows water to be applied in the appropriate amounts, never coming close to field capacity, which your recommendations imply to surpass.

Again what watering practices did I recommend? None. Besides there was no discussion of your methods, so why do you feel the need to accuse me of challenging you or your methods?

Rather than blame under watering for nutrient lock up i would look to the unscientific approach you take to the actual available profiles of the application mix you are using, (as you pointed out in "the myth, of the high p myth.") I am sure that that lack of attention creates much more variance in the media profile then "under watering." If, in fact, "under watering" contributes to an imbalance at all.

Simple logic is adequate as is known scientific testing.

All of our warehouses reuse our co-co (never is it wasted) and thus if it were ill managed in some way would be readily apparent. In fact the opposite is the case. With each reuse the co-co gets better and better.

So you say.

Here is one example of our warehouses that use both coco and Hydro on site. both media receive the same nutrient applications btw.

https://www.icmag.com/ic/showthread.php?t=215910

So what. Simply using the same nutes for two different applications does not mean one or either is actually receivng the best of nutrient formulations available. Some setlle for less thhan good. Some work for better than just good enough.

If you would like to see more there are 20-30 of my threads on the farm you can check out, and a few examples below.

I see no need to look at scads of photos of a large grow operation that at best show the abilities of a hobbyist grower.

Fatman how come you do not post any pictures of your work? At any rate i would be happy to move to a coco or micronutrient thread to discuss this further because it simply has nothing to do with nitrogen, the subject of this thread.

I do not post photos to growing forums as I feel one conviction for drug manufacturing was enough. Photos of mj growing posted online are admissible in court as showing the propensity to commit the crime of drug manufacturing and are not considered prejudicial as they have been willing post in a public forum.

At any rate i would be happy to move to a coco or micronutrient thread to discuss this further because it simply has nothing to do with nitrogen, the subject of this thread.

My reply was simply in response to another posters link posted in this thread. I suggest you talk to him about scope creep if your offended.

As usual your recent posts are just personal attacks with out any worth or value towards helping anyone. I am sorry that you choose to perpetually disagree with any thing and everything I post regardless of the credibility of what I post. I find your personal opposition to all I post to be purely examples of personal problems and that they show display no knowledge of scientific credibility nor do they seem to even share knowledge based upon empirical data.