The myth, of the high P myth?

[Dave Coulier]

love the test dave. im really really surprised that o haze could take that much N. great to see. hope you stop by my thread the myth of low N.

I was a bit surprised too, but in the future Im going to keep N around 150 ppm for her and other strains Im running. My soil test came back with high levels of Nitrates, so even though she could tolerate it for awhile, Im not gonna do it again .

I do have two clones of her in flower now, who are being fed 59 PPM P, and 226 ppm K. I was thinking of increasing K around day 40 to try and duplicate the floral outburst, but at the current K level I am running, Im unsure if Ill be able to replicate it. Ill sill do it as I can't pass up an opportunity to do a little experimenting.

I saw your N thread, and read it a few days ago. I definitely dont believe in the low N . Im currently feeding my crop at 150 ppm N, and Im pretty happy with the results right now.

 

[Dave Coulier]

I thought I would share my current formula I am using now, and share a few pics of Mr. Nice Shit x (Sam's O.Haze x Skunk #1). The mom is the lady in the previous pics. Shit/Haze.

Total PPM:
TN... 148
NN... 108
AN...40
P... 59
K... 226
Ca... 26
Mg... 26
S... 59
Si...26
Fe.. 3.48
Mn... .65
Zn... .65
Cu... .44
B... .18
Mo... .13
total PPM = 570

You'll notice my Ca levels are quite low, but a recent soil test said to stop using Cal/Mag as my Ca/Mag levels were very high when used at a mix of 2.5 and 5.0 ml/gallon. Ever since then, I have avoided a mysterious nutrient deficiency that has plagued me from day 28+ in flowering whenever I used Cal/Mag. Im currently at day 41 of flowering(57 days from seed), and I have avoided this problem.

I haven't had my media tested prior to use, nor had my water tested, so Its entirely plausible it was multiple factors contributing to the problem. Mullray already mentioned this before, but I think we get too concerned with fertilizer PPMs, when we need to look at our soil and our water source and factor them into what our nutrient solutions will be.

The last picture shows N deficiency, but thats mainly a result of moisture stress from when I was hand watering. Now they are on Blumats, and doing much better.

 

[Dave Coulier]

I just now remembered Hammerhead grows his plants at pH up to 7.6. At that high of pH, P availability is reduced, thus requiring higher ppm of P to counteract the alkaline conditions.

I wonder how well his P levels would do, if he kept his pH closer to 6.0, but because his fertilizers N is mostly in the Nitrate form, it wont be possible until he switches to an Ammonium or Urea based fertilizer to reduce the pH.

 

[desertsquirrel]

i drop ph to 5.0-5.4 for P uptake... great point dave.

 

[spurr]

Yea, IIRC Hammerhead uses a pH chart that shows higher P availability above 6.5! And he wrote his media has pH ~7+, IIRC. Many people aren't aware high(er) pH effects (reduces) solubility of P in very similar ways to the solubility of Fe and other metals.

Good point Dave.

 

[Hammerhead]

i DONT FEED MY PLANTS AT 7.5. you REMEMBER THAT POST professor Spurr i SAID 6.5 IS WHAT i USE.
I USE ffof+fflw+perlite. This is PH buffered to 7 with D lime. I use 6.5 ph and 1000ppm right now.
If you guys would just leave me out of your discussions I wont bother you any further. So please just leave this be OK. Keep your discussion going you dont need my name used any further.

 

[Dave Coulier]

Hammerhead, I wont mention you in any more posts after this, but the pH of your feeding solution isn't nearly as important as your media pH. The media pH will have the greatest effect on the availability of nutrients. In your case, the Nitrate N of your fertilizer will continue to keep your media pH rising, and D. Lime wont be of help. It can actually do more harm when paired with a high NN fertilizer.

I hope you dont think Im singling you out. Im only pointing out things that should be considered when designing our nutrient program. Hopefully, it'll be of use to someone.

 

[Hammerhead]

I dont see that. When I FEED AT 6.5 WHEN I check runoff witch I never do sometimes its alwya lower then 7 for veg to flower. my ave is about 6.8


nope but after 35 years of growing I dont see these issues you all speak of. So like I said many time if its not broke dont fix it. You all can continue to experiment. I dont need to. I was assured by my Mentor she is a botanist with a degree. I have nothing to worry about and she had not Idea why I was even asking. she said LOOK AT ALL THE PLANTS YOU HAVE GROWN WHERE IS THE PROBLEM . i started laughing i WILL JUST AGREE TO DISSAGEE. WE WILL LEAVE IT AT THAT GROW WELL

Just for you I measured my runoff using 2g of ro/di water Average Runoff is 6.56 PERFECT This is after 8+ weeks of flower.

Plant#1 6.5
Plant#2 6.6
plant#3 6.6

 

[Avenger]

spurr, dave,

I still don't see where you guys are coming up with nitrates from the PBP.

Can you fill me in?

 

[desertsquirrel]

cal mag avenger..

really hammer your mom? said that about all 3 of your plants? sorry to give you shit man i like your work too. i just couldnt help myself.

 

[Hammerhead]

LMFAO ^^^^^ SO MUCH FOR LEAVNG ME BE A?

 

[Dave Coulier]

HH, I apologize for saying you grow at pH up to 7.6. I was thinking of the 7.6 pH thread from before, but by your own words, you have grown plenty of plants over 7.0 pH, and even contend growing at 7.6 wont be an issue.

I would like to ask you how you measure your run-off? The pour-thru method isn't as accurate if not done correctly.

If measuring run-off directly after watering, then you may get inaccurate results. The media should be completely saturated, allowed to drain for an hour, then use enough Distilled Water to produce 50ml of leachate. That leachate will give you the most accurate results you'll get via Pour-Thru method.

Also, was your pH meter calibrated before testing? I know my Hannah is notorious for needing recalibration each week. Are the BlueLabs worth the money?

 

[Avenger]

cal mag avenger..

Reallly?? I don't remember reading that HH used cal mag, atleast not in this thread.

what do you all consider high P?? I use PBP with Canna 13/14 ad I have massive flowers. I have been using PBP for years. I just started the Canna 13/14 and its has mad a big improvement in bud size for me.

But this is what piqued my curiosity:

PBP Bloom (Soil):

N 1%
P2O5 4%
K2O 5%
Ca 1%
Mg 0.5%
at 15 ml per gallon (by ppm):
NN = 42.7
AN = 2.2
P = 78.6
K = 186.3
Ca = 44.9
Mg = 22.4
__________________

So where do you think the nitrates come from in the PBP bloom soil?

 

[Storm Shadow]

That Blue Lab Meter HH has is pretty sick..I have it as well and it never needs to be calibrated..i might have calibrated mine once in the last 3 years

 

[spurr]

Hey Hammerhead I agree with YS re the bud pic you posted. Looks sweet. Keep on posting so I can imagine smoking some decent dank

Do you not grow? You have mentioned something about not smoking and growing before in this thread.

 

[spurr]

spurr, dave,

I still don't see where you guys are coming up with nitrates from the PBP.

Can you fill me in?

PBP Bloom (soil) lists nitrogen as 1%, but doesn't list the form of N; so I assumed .95% NO3 and 0.05% NH4. Do you know differently? I assumed little NH4 because the process of nitrification would convert much NH4 into NO3; even in the bottle, AFAIK (unless the pH is so low bacteria are inhibited, ex., as with the case of fish hydroslate).

The sources of N listed on the bottle are a mix of NO3 and NH4 sources, but AFAIU mostly NO3. Ex., due to nitrification of seabird guano during "composting" (even if that just means aging), also IIRC, fish meal is comprised of mostly NO3, not NH4, in terms of N.

But I could be wrong.

 

[spurr]

I dont see that. When I FEED AT 6.5 WHEN I check runoff witch I never do sometimes its alwya lower then 7 for veg to flower. my ave is about 6.8

The main point still stands, the pH of your soilless solution is too high with respect to ideal pH for peak solubility of phosphates. Also, if you're checking soilless solution pH when you fertigate, you are not reading the soilless solution pH correctly. Dave mentioned it in passing, as did I, you should use the NCSU PourThru method to test media (i.e., soilless solution) pH (and EC).

What this is about, is the fact P (as phosphates) have highest rate of plant uptake at weakly acidic pH, ex., 5.5-6.2. So, if youre runoff is reading average of pH 6.8 we may assume (but can be wrong), that the 'real' pH is higher, probably average of 7 or greater. Thus, (probably) for you're plants to get sufficient P you need to provide more P than people using ideal soillless solution pH, because more of your applied phosphates are made insoluble (non-plant available) than phosphates for growers using ideal pH.

Also, FWIW, that pH chart you post is very flawed, it's not correct. I would suggest not following what it lists.

nope but after 35 years of growing I dont see these issues you all speak of. So like I said many time if its not broke dont fix it.

You don't see them, because they aren't to point of extreme hindrance to the plant, or you make up for the brokenness (re pH) by over-applying some elements.

I really don't care if you 'fix' your pH or not. That said, your belief that you're doing everything ideally is what you really should fix, IMO open your mind to what all of us are suggesting, you don't have to agree with us, but don't be so closed minded about science.

You all can continue to experiment. I dont need to. I was assured by my Mentor she is a botanist with a degree. I have nothing to worry about and she had not Idea why I was even asking. she said LOOK AT ALL THE PLANTS YOU HAVE GROWN WHERE IS THE PROBLEM . i started laughing i WILL JUST AGREE TO DISSAGEE. WE WILL LEAVE IT AT THAT GROW WELL

If she really told you that you need a new mentor, seriously. Any botanist should know you can tell as much about the health of plant by just looking at it, as you can about the health of a person by just looking at it.

Just for you I measured my runoff using 2g of ro/di water Average Runoff is 6.56 PERFECT This is after 8+ weeks of flower.

Dave listed how to test media pH, it's not by using 2 gallon of ro/di water, which would show a lower pH than the true pH of your soilless solution, IME. Also, what do you mean by ro/do? Is it RO or DI, or a mix? RO and DI are very different beasts, well, that is in the case of what growers call RO water where the "RO water" still has ions.

Even still, pH of > 6.2 is too high to be called "perfect" for cannabis and other plants that prefer weakly acidic media and rhizosphere.

 

[Dave Coulier]

That Blue Lab Meter HH has is pretty sick..I have it as well and it never needs to be calibrated..i might have calibrated mine once in the last 3 years

Thanks. I think Ill upgrade to that next time. Ive gone through so many Hanna meters its ridiculous. They have about a 3-5 month life span at best. Thank you warranty. Lol.

 

[spurr]

Do you not grow? You have mentioned something about not smoking and growing before in this thread.

Semi retired I'd say I've probably grown for more years than you've been out of shorts.

Ha, maybe but I doubt it, I've been growing for about 20 years myself .

I'm smoking absolute rubbish at the moment - why do you ask Spurr?

Just curious, I noticed you've written it a few times. No nefarious motives here, I'm not one of those people that claim you have to grow to know what you're discussing.

Oh and why are you always getting into fights with people. Surely you could learn to discuss things in a way that didn't get peoples hackles up. Just a tip - you may find people take you more seriously.

I could ask you the same thing . I do not always get into fights with people, far, far from it. The only people that have their hackles raised are generally those with big egos that don't like to be shown they are wrong. I get along with just about everyone else; and for the record, I neither have a big ego nor do I dislike being shown I'm wrong (if it's sound info).

Oh yea, people take me serious well enough now, and if they didn't it wouldn't bother me.

 

[desertsquirrel]

we have about a dozen guardians. i love them.

http://www.getbluelab.com/shop/Bluelab+Guardian+Monitor.html