The myth, of the high P myth?

[YosemiteSam]

2 Sensi Northern Lights at 53 and 51 days. Plan to chop at 56. Dtw in 2:1 peat moss/perlite mix under 600w hps. Fed between 80-100%(40-50ppm of P) of a solution containing 160-50-300-180-50 N-P-K-Ca-Mg

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I like the way they faded for you. I don't see any indication of deficiencies.

Thank you for showing me the way I am going is not off a cliff

 

[BasementBreeder]

No massive flush, but I've been feeding those two plants only RO water since approximately day 42. They were a nice shade of green when I began(only in the last 2 days or so have they faded).

 

[YosemiteSam]

a bud pic

a bud pic



low P through stretch, a couple of weeks at 90 P and then back to 60.

 

[YosemiteSam]

I went 40 P through stretch, jumped to 90 for I think 2.5 weeks, then backed it down to 60 and then further down to let the plant finish.

I tend to run plants with a decent stretch just cause of the way I grow. If I were running more indica dom plants I would probably use 60 P in veg.

 

[YosemiteSam]

No question I missed by a hair on Ca.

I am really not sure about Mg. This next go will tell the tale on that.

I find myself wondering how to tell if I overdo it on Mg. I plan to maintain the 2:1 Ca:Mg ratio. It is pretty easy to tell if you undershoot on Mg...but how do you tell if you overshoot...especially if you only do it by a little? My real guess is that it will effect taste...too much and I think it will effect taste, being that Mg is at the center of the chlorophyll molecule.


That may end up being something I tinker with after I solve my Ca issues. Basement Breeder's grow definitely indicates I may be pushing it a little bit...but will it do any harm???

More questions than there is time to answer them. One thing I know for sure...if you feed your plants water as long as BB did and they fade without showing any true deficiency...you got to be pretty fucking close.

Those pics impressed me.

 

[YosemiteSam]

2 Sensi Northern Lights at 53 and 51 days. Plan to chop at 56. Dtw in 2:1 peat moss/perlite mix under 600w hps. Fed between 80-100%(40-50ppm of P) of a solution containing 160-50-300-180-50 N-P-K-Ca-Mg

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btw BB...would you mind sharing your actual formula? That is the salts you use. it is actually very difficult to achieve that much Ca and K at the same time. If you supply the Ca with CaNO3 you end up shorting yourself on K...then you are stuck with possibly K2SO4...and at some point you would worry about CaSO4 precipping out.

How did you solve that dilemma?

 

[BasementBreeder]

Nice lookin' plant you have there YS. When my current gallon of stock solution is up I plan on upping(and lowering) P levels very similar to what you have done.

Anyway, my tap water as analyzed by lab:

soluble Salts mmhos/cm .800
Calcium ppm 85.8
Magnesium ppm 17.9
Nitrate ppm .690
Ammonium ppm 2.37
Urea ppm .640
Phosphorus ppm .56
Potassium ppm 3.19
Sulfur ppm 19.2
Sodium ppm 59.2
Chloride ppm 94.2

I use a 50/50 mix of tap and RO as my base(so cut above numbers in half). To prepare my A and B stock solutions(1:100 dilution for full strength) I mixed per gallon(as well as I could with my scale):
A
168.663g KNO3
312.514g Ca(NO3)2.4H2O

B
157.598g MgSO4.7H2O
82.701g KH2PO4
53.424g K2SO4

pretty sure I threw some micros in there too

This formulation is via the Hydrobuddy nutrient calculator.

 

[Oldmans_Herbs]

i like to keep the same nutes going till flower, then i raise the p and k for a couple weeks then lower the p back down keeping the higher k. just my input.
Herb

 

[YosemiteSam]

Thanks BB...that is a very nice formula. May I ask which CaNO3 you are using?

Mullray...I use a product from Albion (http://www.albionminerals.com/plant-nutrition) called Metolasate Calcium. Instead of edta chelation it is a true amino chelate. I am having very good success with it...although the test seems to come about 5 weeks into flower.

I did that for exactly the reasons you stated...to reduce my K:Ca ratio. There is only so far you can go with CaNO3...although BBs CaNO3 looks like it may provide more Ca than the Yara Liva I am using.

 

[Overthinker]

First can I say this in a great thread. Cant even count how many times I have read through it. Thanks to everyone who has put forth their experiences & knowledge.
YS,
you have inspired me to deviate from the head formula. I am new to coco and had troubles. Went to the head recipe and it seemed to cure the problems I was having. However since following your results here and on another site I was convinced that my fertigation program was definitely falling short. I don't have dry salts to work with however I have bottles out the yanger... lol Anyway I have been using a calc and mixing a witches brew to try to get some control over what I am doing. Heads formula has relatively low P compared to what many people use(I don't know if it would be considered "low" in the context of this thread). I am convinced that I was way short on K though.

Anyways, I am beginning to ramble on... sorry.
I have come up with this schedule for now. I am in week three and seem to be blowing away results with 6/9 recipe. Not sure if the low P is the reason but their is better structure, rate of growth(not stretch), and overall health. I plan to up the P in latter weeks but may test it lower to harvest next time around.
Any and all comments & suggestions are greatly appreciated, as I am just starting to wrap my head around proper nutrition and cation ratios.

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Again, Great thread, thanks Spurr, Mullray, Y-sam, Analog, Tester,.... uh yeah everyone!

O

 

[YosemiteSam]

Overthinker...welcome to the dark side.

I think (H3ad may disagree) that the 6/9 formula lacked K more so than it lacked P.

Your formula looks good but it is my opinion that you would be even happier if you raise your cation ratio relative to N. That is, if your N is at 125 I think you can go up to 250 on K and then you would need to raise Ca and Mg accordingly...and I think K:Ca:Mg should be somewhere from 4:2:1 to 3:2:1.

Anyways, nice job and I am glad your results improved.

Love those charts btw.

 

[Overthinker]

YS,
Thanks for the greating to the dark side... lol
I can hardly stand to go into the nute stores now and hear about how AN and this and that has triple chelete bla blah... I dont know @#$% but what my rep fed me.

Anyways, I greatly appriciate your advice. baby steps, baby steps. I am also a little scared of getting my ec up as I run blumat drippers with no runoff. Occasionally when I do a res change I will water the old solution out through the containers(my version of a flush, ie. some runoff. lol) The runoff ec scares me, however I am still creeping it up and everything just seems to like it more and more.

Since this is the P thread I dont want to stray to far off topic. Do you think I am cutting it out to soon or too late? I understand I want mainly the P & N out by the end. Last time went 10weeks, (I believe due to some granular ferts I added to my coco to late). I really doubt this run will have the delayed maturation issue as I am pretty sure my head is completely removed from my arss now. Liquid salt feed only, I have had zero deff, zero issues, and will also be able to contribute to the anictdotal evidence on the cal25... lol I am expecting things to complete by end of 8 to end of 9 depending on variety.

Anyways thanks again, I really like your stlye. Maybe I will have to stop in on your Journal and pic your brain some more if you dont mind.

O

 

[staff11]

Isn't the delaying of maturation caused by other things as well?

I am just curious because I have had plants grown in soil (With plenty of amendments, I usually use the old soil for cooking herbs and they grow with just water..) that just finish when they well for lack of better term FINISH....

No adjustment in nutrient levels as I used compost teas to water with. (Have since changed, don't have the time or room for brewing anymore)

I think other factors can come into play as well.....

 

[Overthinker]

Isn't the delaying of maturation caused by other things as well?

I am just curious because I have had plants grown in soil (With plenty of amendments, I usually use the old soil for cooking herbs and they grow with just water..) that just finish when they well for lack of better term FINISH....

No adjustment in nutrient levels as I used compost teas to water with. (Have since changed, don't have the time or room for brewing anymore)

I think other factors can come into play as well.....

You are correct. but in my situation I believe that it was the high N in the end when the n should have been going away. Every factor of my climate is completely controlled. So I believe for my situation it was most likely my horrible feeding regimen. I am positive that high N in the final weeks was not my only issue as fas a feeding goes.
I learned I don't have the finesse for granular ferts in such a short cycle. Anyways, any thoughts on the new schedule. I hope I am cutting the P out soon enough. I really do see better structure during stretch from keeping my P under 60, which is not very low in terms of this thread but is much lower than I had previously run and, much lower than what most others advise.

O

 

[YosemiteSam]

I think those are great questions and I have given them considerable thought. Here is my current thinking.

I think environment plays a big part in how fast a plant finishes or not, what its exact nute requirements are, etc.

About when a plant finishes and its nute requirements late in life. I think genetics plays the biggest role obviously. I think certain things, like say triacontonal can shorten that but only to a degree.

So you have certain genetics, a certain environment and your running along. Regardless of what you do the plant is going to go into sensense sooner or later...I don't think you should try to influence when that happens (other than by providing the best environment you can and possibly tria). When it does its nute requirements are going to drop.

When they do the question becomes do you just reduce food or do you "flush". And it just so happens that is one hotly contested issue.

If you switch to water only you are going to get deficiencies...the plant is still alive and still has food needs. But if you overfeed you are going to end up with not so good tasting weed.

If you intend to actually cure your weed you can cut back on food...I start at the beginning of week 6. Your cure will then eliminate chlorophyll and taste will be good..

If you do not actually cure then you may want to flush with nothing but water. That allows it to taste good without a lot of cure.

But...when you just use water and get those deficiencies you are making the plant susceptible to disease. You are much more likely to get mold, PM, mites, etc at this point than any in the grow.

What you want is a fade like Basement Breeder got...no spots on the leaves, etc.

Anyways, at the beginning of week 6 I start cutting back the EC but basically maintaining ratios...so N goes down, P goes down, K goes down. Then about 2 weeks out I cut back N and P a little more.

Is it the best...I don't know. I am still playing.

The goal, though, is white burning ash and flavor to the very end of the bowl. I currently get the white burn and good "green" flavor but it drops off slightly as the the bowl gets smoked...so I got some work to do in that area.

 

[Overthinker]

Thanks for the welcome mullray,
I have learned much from your posts in several threads. Your knowledge is well appreciated.
The darkside is a great place, at least in this context...lol I definitely plan to switch to dry salts as soon as I finish all of these bottles of magic potion. I am actually able to control things to some extent inputting the vast array of products I have into a nute calc. However due to the way they are formulated I am having the hardest time getting the calcium up without raising the N so much. All of the calcium rich products I have simply have to much N along with the Ca. Also finding a source of K from bottles that doesn't drive up the N or P too much has been a challenge. Pro-tech Silica has been the go to for the time being.

Where P is concerned; I think from what I am seeing there is some truth to the "high P myth" being a myth(at least in stretch). I am not brave enough to leave it so low strait through.
Also, I believe that dry salts are almost the only way to get any real control over your ratios. From what I can tell it is very difficult to obtain good cation ratios while keeping the P in the lower range. As most sources of K in commercial hydro nutes are either in a "grow" formula which brings much N and no Ca, or in a "bloom" formula which brings to much P if you are looking to push up the K to ideal levels. I have been managing for now but I believe I am using about 7 or 8 products to get a bit of control over what is in my feed and still don't have enough variable to be able to really push on the K(which seems to be where most peoples experience leads me to want to go). CES make a Ca(plant amp) product that would help me finish off all of this junk with a ton more control, However this price is NOT right. I think a nice blend could be found from Earth Juice micro blast, CES grow, CES plant amp, with some silica and epsoms. but would probably cost 10 times the dry salts to do it myself.

YS,
I bye no means have any solid understanding of all of the intricacies of sensense. However things were finishing up, and when I cut liquid feed, it seemed to me that the granular ferts kept feeding(probably at some extremely terrible ratio) and the plant seemed to have a deficiency riddled attempt at resuming growth. Old calyxes were as big as a house(some even appearing to attempt to die), with some foxtailing beginning, cloudy Ts, and weeks later not even 1 amber. I should have culled long long before this point but... yeah I know, I know. Live and learn.
I don't plan to make any attempt to solve this mystery, I just plan to forget about what a moron I was that run. Ya know, stuff the memory of that crop into that little trash bin corner of my brain so I can get back to thinking how smart I am...lol
Anyways, it seems I am in the ballpark of your methodology when it comes to finish feeding(or at least on the same block as the ballpark). I have the N beginning to fade starting in week5. then really dropping off after that, I bumped up the P for week 6 & 7 then it's cut out quick.

We'll see how it goes. I am in week 3 and have plenty of time to make adjustments if someone is so willing to help steer this wayward ship. No matter what it cant go any worse than last time.

Thanks again everyone, O

 

[spurr]

I know of no reason to foliar feed the Ca and Mg on different days. Seems like extra work to me.

Me either, it's fine to do so at the same time with a caveat of POD:

The only issue is the RH of the room at canopy. The RH has to be above the POD of the elements, if not, once the leaf is 'dry' the elements will no longer be absorbed. Ex., if using CaNO3 and MgNO3 spraying together is fine as long as the RH is above 53% (the POD for CaNO3 and MgNO3); however, if using CaNO3 and MgSO4 (Epsom salt) they should not be used together if the RH is not above 60% (the POD for MgSO4). The POD of many amino acid chelates is quite a lot higher, up to and around 80-90% RH.

 

[spurr]

View attachment 110868

40 P through veg, 60 P through stretch...it was 17 days into flower when the pic was taken.

K:N ratio is being bumped to 2:1 for the rest of the grow...136 N

Gonna find some stuff out this time.

The plant is an ISS and is literally 8 ft in diameter. I expect big things from it

Hey YS,

My plants (~20 GrapeGod) are starting the second week of flowering today. The plants have never gotten over ~52 ppm P, up until about a week ago I was using ~39 ppm P and now I changed to ~52 ppm P. Plants are healthy and doing great, I will post up current pics soon(ish). The reduced stretch/interonde lengths I have seen this time (as before) are very welcome, from the reduced P ...

Some pics of my current grow are in my album (link to album), the pics are of the plants weeks ago*. Below are a couple of older pics and a screen shot of my current test mix using commonly found hydro fertilizers** (so others can copy if they wish), compared to the PH/Lucas mix.

* In that album are pics when I was testing low and high irradiance effects on seedlings; re: the very stretched seedlings (I'm not a bad grower, I promise!). Basically, I provided 100 umol/area/second to seedlings for about a week or so, until they were stretching a lot, then I increased the irradiance to 250 umol/area/second and then 500 umol/area/second. I wanted to look into sufficient irradiance for seedlings. From my very simple tests, 500 umol/area/second is what I will use until I have a chance to more thoroughly/correctly study the issue.


** I have sending in fertilizer samples of everything I use to get tested at a lab, as a means to double-check the label and get finer grained info. I had some personal stuff to take care of the past few months, I will provide more info soon ...

 

[YosemiteSam]

Hey YS,

My plants (~20 GrapeGod) are starting the second week of flowering today. The plants have never gotten over ~52 ppm P, up until about a week ago I was using ~39 ppm P and now I changed to ~52 ppm P. Plants are healthy and doing great, I will post up current pics soon(ish). The reduced stretch/interonde lengths I have seen this time (as before) are very welcome, from the reduced P ...

I agree with this. I too think low P reduces the stretch and improves internode distance. I also agree a plant can be healthy its entire life on no more than 40 ppm P. I would even go so far as saying it will yield just as well at 40 all of the way as it does at higher levels.

But for me I find that bumping it after stretch is done increased my trich production...significantly

 

[YosemiteSam]

Yields on 15 lights were within a pound of each other between the 40ppm grow and the one that went up to 90. Genetics were not exactly the same so no way is a pound significant.

Quality did improve though.