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The myth, of the high P myth?

Y

YosemiteSam

Here are the exact formulas I am currently running.

veg...through stretch

cano3...3
mgso4...2.4
kno3...0.7
mkp...0.4
micro...0.1

150-24-101-144-60 (peak formula normally run at lower concentrations)

flower

CaNO3...3.7
mkp...0.8
mgso4...2.4
met k ...2.6
micro...0.1

150-48-240-177-60 (pretty much run at that level or a hair higher)

So that is almost exactly in line with your K:N the_extremist. On a 10 week strain I start feeding the flower formula at the end of week 3 (pretty much the end of stretch on my 10 week strains). At the end of 7.5-8 weeks (depending on how green they are) I quit feeding N and basically just feed a little K and a couple of other minerals...to let the coco rid itself of N and for the plant to have the other things it needs while the N is getting used up. Somewhere between a week or 1.5 weeks out I go to water only.

As to EC or ppm N or however you want to call it, how strong to feed them...that depends on your media and your growing method. DS is feeding around 1/2 strength in an UnderCurrent, I am feeding 150-200 ppm N in 65 gallon pots that I fertigate every 3-4 days (playing around with O2 management at the time). In the end though a pound of either of our bud probably used similar total cumulative amounts of nutes.

However, I will say if you are in coco and in pots that need watered every day the 115 N is going to be pretty close to what you need. You just have to watch how green they are and you kinda want the bud doubling in size every week...so you watch and tweak.

Ratio wise though that looks like a good formula to me

I have quit using Si in my res. The stuff seems to act a whole lot like carbonate...that is buffering the pH of my media constantly upward.

I am, however, going to foliar feed it once or twice in veg and once in flower. It is most excellent in preventing PM on tomatoes when used that way...in spite of other plants in the area having it.

Hope that helps.

edit...S would be 79 on both my formulas.
 
Awesome, thanks for the quick response and the details. Class act as always, sir. Killer info.

edit: have to spread rep around before I rep you again, but I would if I could, lol.
 

max_well

Member
I'm curious about the ppm contribution of calmag plus.
Label says 3.2% calcium, %2.0 nitrogen, %1.2 Mg derived from the sources, Calcium Nitrate, Mag Nitrate, (and also Fe EDTA).
http://www.americanagritech.com/supplements/cal-mag
How could the N/Ca ratio be this high using Nitrate as calcium and magnesium sources? CalNit alone contributes a 1.2 Ca to 1 N ratio of ppm, and the use of Mag Nitrate as a Mg source will also contribute to N... so how could the ratio end up as 3.2 to 2 for Ca to N?
thanks for any insights!






So here's what I plan on running in coco coir come spring time when I finally run out of super soil.

Botanicare Pure Blend Pro Hydro Bloom @ 10ml/gallon
N----P----K---Ca--Mg
61--40--126--30--15

Botanicare CalMag+ @ 10ml/gallon
N---Ca--Mg
54--86--32
Epsom Salt @ .5g/gallon
Mg--S
13--16

Sulfate of Potash @ .5g/gallon
K----S
55--24

Total Before S of K:
-N----P----K----Ca---Mg--S
115--40--126--116--60--16

After S of K:
-N----P----K----Ca---Mg--S
115--40--181--116--60--40

I'm curious about when in flower to add the K sulfate for a 70 day strain. I was thinking about starting around day 40 or so when they really start stacking and running it up until flush time. From what I've read, coir can be fussy when K levels get too high. How high is too high? Can anyone who's worked with coir offer advice? (YosemiteSam, I'm lookin' at you, brother)

Also, I'm under 1kw's with CO2. Do you guys think this mix will keep the ladies fed? Or will I need to bump up the EC of the mix to compensate?
 
Y

YosemiteSam

I'm curious about the ppm contribution of calmag plus.
Label says 3.2% calcium, %2.0 nitrogen, %1.2 Mg derived from the sources, Calcium Nitrate, Mag Nitrate, (and also Fe EDTA).
http://www.americanagritech.com/supplements/cal-mag
How could the N/Ca ratio be this high using Nitrate as calcium and magnesium sources? CalNit alone contributes a 1.2 Ca to 1 N ratio of ppm, and the use of Mag Nitrate as a Mg source will also contribute to N... so how could the ratio end up as 3.2 to 2 for Ca to N?
thanks for any insights!

I think you may be confusing % of an element in a bottle to ppm in a reservoir.

For example, CaNO3 (at least Yara Liva)...when a gram is dissolved in a gallon of water provides 41 ppm N and 48 ppm Ca.

Then they tend to add MgNO3 because they want to avoid the SO4 from epsom salts...cause Ca and SO4 do not play well together in concentrated solutions.
 

max_well

Member
I read standard fertilizer grade Calcium Nitrate ( http://docs.google.com/viewer?a=v&q...Fgzx-z&sig=AHIEtbRkRw6p8PicsxBrwvbFZcNN1PlMlg ), for example, described as ~19% calcium and 15.5% N, and gives this same ratio of ppm contribution as I understand it (~1.2/1 Ca/N, same as 48/41ppm you give as an example with a gram per gallon). However the back of the bottle states a 3.2% Ca, 2% N. And I see people calculate their resultant ppm contributions in this ratio (see post from 'the_extremist').. Suggests there must be another calcium source beyond the calcium nitrate source listed?

I think you may be confusing % of an element in a bottle to ppm in a reservoir.

For example, CaNO3 (at least Yara Liva)...when a gram is dissolved in a gallon of water provides 41 ppm N and 48 ppm Ca.

Then they tend to add MgNO3 because they want to avoid the SO4 from epsom salts...cause Ca and SO4 do not play well together in concentrated solutions.
 
Y

YosemiteSam

I read standard fertilizer grade Calcium Nitrate ( http://docs.google.com/viewer?a=v&q...Fgzx-z&sig=AHIEtbRkRw6p8PicsxBrwvbFZcNN1PlMlg ), for example, described as ~19% calcium and 15.5% N, and gives this same ratio of ppm contribution as I understand it (~1.2/1 Ca/N, same as 48/41ppm you give as an example with a gram per gallon). However the back of the bottle states a 3.2% Ca, 2% N. And I see people calculate their resultant ppm contributions in this ratio (see post from 'the_extremist').. Suggests there must be another calcium source beyond the calcium nitrate source listed?

the bottle may have used a different cano3...the 19/15.5 is pretty standard but it could be almost anything depending on the mfg...

or they may flat be lying...the state of OR has found many cases of that...just ask Big Mike.
 
Y

YosemiteSam

Surly some high p people will comment?

Half way into flower, 30 ppm P and a little bit of P acid to control my 50-60 ppm alkalinity water without using much NH4. I ain't gonna argue with you mang.

DSC_0006.jpg

edit...its not easy to get em to grow sideways like that...DOH
 
Y

YosemiteSam

Yes...in coco. I will post a pic when we chop it...around 11/3. It really is totally ridiculous now. I personally see no need at all to go over 30 ppm P.
 
Y

YosemiteSam

very nice. what strain?

Mob Boss by Grindhouse. It tends to put it on like this regardless...but I will post some of the other stuff growing with it. Pretty happy about trich production on this grow.

edit...I will save you a bud from the Mob Boss to try.
 

L420K

New member
i apologize for not having the patience to read through all 51 pages :clown: but I think it is interesting the analysis reports show low levels of P, however a new issue is the fact that phosphate is an energy unit, in the form of ATP. The flowering phase is an explosion of growth, is ATP conserved or used and is it viably mobile, or do new tissues need new sources? I think these questions will lead to some interesting insights into the discussion here.
 
Y

YosemiteSam

untitled (1 of 1)-4.jpg
Prophet

untitled (1 of 1)-3.jpg
ISS

untitled (1 of 1).jpg
Mob Boss

untitled (1 of 1)-2.jpg
Mob Boss

These came out pretty good...all at 10 weeks but it was not my best grow. You can see by the purple stem on one of the Mob Boss pics that 30 ppm P was not really quite enough P. MB tends to purple stems anyways but this was a little much.

I am now running my P equal to my Mg...both at 60 ppm when I am at 125 ppm N.

We switched to 65 gallon smart pots and it took me a while to dial in watering.

Anyways...you can run really low P but when you do it better be stress free...at least in my experience.
 
Y

YosemiteSam

I think it depends on your growing method. For me, in coco dtw, I see no need to go over 60 ppm P. For recirc someone might have to go a little higher just to help buffer pH. For someone in a UC you probably need only 1/2 the nutes to begin with so 30-40 ppm P.

Both MB buds are off the same plant. I got a little foxtailing on a few of the buds. MB is definitely dank and nicely balanced between indica and sativa. And it yields well making it one of my favorite plants.
 
jaw dropping grows.

i would like to know the verdict on the DeuceDeuce 0-0-22 pls.

?also a Question for YS and DS: are you using all HPS lights, or a combination of hps and MH?
 

TanzanianMagic

Well-known member
Veteran
I have been doing a lot of reading regarding the high phosphorous myth and how it is a waste to use bloom boosters with obnoxiously high amounts of P.
This year I am going to experiment with switching from high P/K throughout bloom, to high P in early flower, to high K in late flower.

KOG has a video on youtube where he feeds his outdoor plants ashes (high K) a month before harvests, which gets him bigger heads.

So maybe that is the way to go - and the answer to preventing P buildup in the soil in flowering.
 
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