420 Magazine Background

Do we need to pH adjust our nutrient solutions?

Marzbadrock

Plant of the Month: Sept 2015 - Nug of the Month: Jan 2016, May 2018
Here it is

Medium
1 bag ffof
1/2 cup pelletized dolomite lime
Mix that up thoroughly

Nutes
Nature's nectar
Nitro
Phosphate
Potas.

I veg my plants about 5 weeks using water only. I start in #1 poly pots, transplant into #5 once roots established. If vegging longer you'll need to transplant to #7 or feed nutes.

Week 1, 2
N- 5 ml per gallon
P- 3 ml per gallon
K- 3 ml per gallon

Week 3, 4, 5
N- 5 ml per gallon
P- 5 ml per gallon
K- 5 ml per gallon

Week 6, 7
N- 2 ml per gallon
P- 5 ml per gallon
K- 7 ml per gallon

Last 10 days water only! Feeding regimen may need adjusted slightly for longer or shorter flower times. I followed this recipe with great success butvhonestly I don't even measure any more, just a glug of this a splash of that. I never have a single deficiency until I cut the nutes.
 

Mr. Magoo

Member of the Month: Sept 2018 - Plant of the Month: Mar 2019 - Nug of the Month: October 2019
Here it is

Medium
1 bag ffof
1/2 cup pelletized dolomite lime
Mix that up thoroughly

Nutes
Nature's nectar
Nitro
Phosphate
Potas.

I veg my plants about 5 weeks using water only. I start in #1 poly pots, transplant into #5 once roots established. If vegging longer you'll need to transplant to #7 or feed nutes.

Week 1, 2
N- 5 ml per gallon
P- 3 ml per gallon
K- 3 ml per gallon

Week 3, 4, 5
N- 5 ml per gallon
P- 5 ml per gallon
K- 5 ml per gallon

Week 6, 7
N- 2 ml per gallon
P- 5 ml per gallon
K- 7 ml per gallon

Last 10 days water only! Feeding regimen may need adjusted slightly for longer or shorter flower times. I followed this recipe with great success butvhonestly I don't even measure any more, just a glug of this a splash of that. I never have a single deficiency until I cut the nutes.
Sounds like a winning combo!
 

Weaselcracker

Nug of the Year: 2016 - Member of the Month: Sept 2015, Nov 2016 - Nug of the Month: Oct 2016 - Plant of the Month: May 2016
Well into flowering now, and the victims are both fine despite horribly high and low ph levels. One is being fed at around 3 and the other one between 8.5 -10.


Three gallon pots, for perspective.
Crappy pics but you can at least see they’re reasonably healthy.
Good news, I guess. Confusing though. :hmmmm: I don’t know how it fits with my past experience. I still plan to write that pH expert when I get time, I’ve just been very busy, plus also been doing a number of other different pH tests on the side. So I’m slowly putting together an email for him and hopefully will eventually learn something real. :48:
 
Last edited:

Marzbadrock

Plant of the Month: Sept 2015 - Nug of the Month: Jan 2016, May 2018
Well into flowering now, and the victims are both fine despite horribly high and ph levels. One is being fed at around 3 and the other one between 8.5 -10.


Three gallon pots, for perspective.
Crappy pics but you can at least see they’re reasonably healthy.
Good news, I guess. Confusing though. :hmmmm: I don’t know how it fits with my past experience. I still plan to write that pH expert when I get time, I’ve just been very busy, plus also been doing a number of other different pH tests on the side. So I’m slowly putting together an email for him and hopefully will eventually learn something real here by the end of flowering....
Love the experiment! I've done alot of side by sides with different nutes n different ph or not to ph....none as drastic as 3 to 10. I'm honestly not surprised though on how well they look, soil buffering doing its job. My current bloom formula usually comes out low 4s to 5 depending on phosphorus level. I use to get minor deficiencies late in bloom, pelletised dolomite took care of that. Something keep in mind if any show up! Looking good Weasel, thankyou for sharing!
 

Elmer Fud

Well-Known Member
Well into flowering now, and the victims are both fine despite horribly high and low ph levels. One is being fed at around 3 and the other one between 8.5 -10.


Three gallon pots, for perspective.
Crappy pics but you can at least see they’re reasonably healthy.
Good news, I guess. Confusing though. :hmmmm: I don’t know how it fits with my past experience. I still plan to write that pH expert when I get time, I’ve just been very busy, plus also been doing a number of other different pH tests on the side. So I’m slowly putting together an email for him and hopefully will eventually learn something real. :48:
What's ur buffer? Lol,,,,,,, that would obviously explain why your girls can handle it!!! Your medium is mixed well, and has great buffer. Did you make super soil? When Adding "lime
dust" and mixing your base good/well enough, you can give them PH 1 and PH 15.... no damage will be done, or very very minimal,, it neutralizes your medium automatically.

Now try doing that test with a plant potted in just reg soil/ or not as good of a blend/recipe... lol, homerowers make me smile from time to time... lol... this is one of them.. :snowboating: :Namaste:

Good night folks.
 
Last edited:

InTheShed

Member of the Year: 2018 - Member of the Month: Jan 2018, Nov 2018, Jan 2020 - Grow Journal of the Month: Aug 2018 - Plant of the Month: Oct 2018
Well into flowering now, and the victims are both fine despite horribly high and low ph levels. One is being fed at around 3 and the other one between 8.5 -10.
Terrific experiment WC! According to many folks your plants should be dead :).
Your medium is mixed well, and has great buffer.
Buffering is what a good soil or soil-less medium is all about! The first thing we do when we grow cannabis is decide what our substrate is going to be. And we should choose wisely, as it is what will support the plant from birth to harvest.
homerowers make me smile from time to time... lol... this is one of them
And we're here to amuse you Elmer! Glad to be able to make your day from time to time lol.
 
Last edited:

Weaselcracker

Nug of the Year: 2016 - Member of the Month: Sept 2015, Nov 2016 - Nug of the Month: Oct 2016 - Plant of the Month: May 2016
Terrific experiment WC! According to many folks your plants should be dead :).

Thanks Shed. I’m quite surprised. I have had major pH troubles in the past in the same mix.
Also as I probably mentioned, I also did a similar though less drastic side-by-side pH test several years ago and it did not go like this one did at all. The high ph plant totally failed.

Compared to a true organic soil mix with a lot of ingredients and buffering functions, my peat moss/perlite/lime ‘soil’ seems to me sorta like comparing Wonderbread to a loaf of whole grain organic. :hmmmm:

The more I read about ph the more complex the subject looks. TBH, I don’t care much about any of it, I just want to not toast my plants! :eek:

I’ll try to put together some sort of intelligible email to the ph guy and hopefully make sense of some of the ph troubles I’ve had in the past.

Here is a good article on peat moss/lime buffering, written by the guy at Sungro I’m talking about.

 

BigD13

Well-Known Member
I've read this thread a few times and it got me thinking about something. I grow outside, in pots, in soil. I use well water that has a pH of 7.4 and an alkalinity of 140 ppm. A couple of the more popular nutrients are FF Grow Big & Mega Crop.

On the FF Grow Big bottle it shows:
Total Nitrogen.......6.0%
2.9% Ammoniacal Nitrogen
3.1% Nitrate Nitrogen

On the Mega Crop (9-6-17) it shows:
Total Nitrogen......9%
8.5% Nitrate Nitrogen
.5% Ammonical Nitrogen

Since the topic is not having to adjust our nutrient solutions, in my case, since my well water is already 7.4 and my alkalinity is 140 ppm, wouldn't I be better off using Grow Big, which has more Ammoniacal Nitrogen, which may help to lower and/or balance out my soil pH?
 

InTheShed

Member of the Year: 2018 - Member of the Month: Jan 2018, Nov 2018, Jan 2020 - Grow Journal of the Month: Aug 2018 - Plant of the Month: Oct 2018
If you are using a well-made commercial soil, you don't have to worry about the type of nitrogen in the nutes you are using. If you were planning on reusing the soil over and over, the buffering effects will diminish with each grow. At that point you would be better off amending the soil rather than choosing a different nutrient line.

I use Los Angeles tap water which ranges from 150-250 ppm (not necessarily all alkaline-related) and has a similar pH to yours. I haven't used a pH pen since December of last year and my plants turned out rather well.
 

BigD13

Well-Known Member
I have a pH pen too, but haven't used it since reading this thread and a couple of others.

I don't use a commercial soil. After doing a bunch of research, I mixed up my own soil. I kind of forgot that one of the things I did was to admend it so it would have some buffering properties. I've been using the FF trio and my plants are doing good.

I got a sample of MC. I'll try it out on my grow next spring. I hope it works for me as well as it does for you. It will be so much easier to use than the FF trio.

I'm subbed on your grow journal. To say your plants turn out rather well is an understatement.
 

InTheShed

Member of the Year: 2018 - Member of the Month: Jan 2018, Nov 2018, Jan 2020 - Grow Journal of the Month: Aug 2018 - Plant of the Month: Oct 2018
Most home made soil recipes include loads of buffers, so that takes care of the pH for you!


And I too went from the FF trio to MC...never looked back :thumb:.
 

InTheShed

Member of the Year: 2018 - Member of the Month: Jan 2018, Nov 2018, Jan 2020 - Grow Journal of the Month: Aug 2018 - Plant of the Month: Oct 2018
I know there was some discussion of the fact that my source at the top of this thread was the manufacturer of ProMix, which caused some to say the information presented was biased because of that.

What ax do the University of New Hampshire and Cornell have to grind?

I point those who are still unconvinced to this pdf file, and in particular section 3 (a good read in its entirety), and in particular 3 D. Fertilizer Type, which states, "You cannot measure the acid or basic reaction of a water-soluble fertilizer by measuring the pH of the stock tank or the solution coming out of the end of the hose. Rather, it is the tendency of a water-soluble fertilizer to change medium-pH over time. Information on any bag of fertilizer will include the acid or basic reaction of a water-soluble fertilizer is written on the bag as an acidic or basic “calcium carbonate equivalency” (CCE), which is a relative measure of the tendency of the fertilizer to raise or lower medium-pH (Table 1). More importantly, the label tells the type and percentage of the different forms of nitrogen (ammonium, nitrate, or urea), as well as the percentage of the other nutrients contained in the fertilizer. In general, ammoniacal and urea nitrogen are acidic, and tend to drive the media pH down, whereas nitrate nitrogen is basic and tends to drive the media pH up."

It continues from there in that section, and moves on to 3 E. Irrigation water alkalinity. All of which backs up the original statement from Premier Tech. Neither biased nor wrong.

[The Blackmore Company sells fertilizer, among other things, just for the record. Do they want your plants to die because you haven't pH'd your nutes when using their product?]
 
Last edited:

Elvin

Well-Known Member
I know there was some discussion of the fact that my source at the top of this thread was the manufacturer of ProMix, which caused some to say the information presented was biased because of that.

What ax do the University of New Hampshire and Cornell have to grind?

I point those who are still unconvinced to this pdf file, and in particular section 3 (a good read in its entirety), and in particular 3 D. Fertilizer Type, which states, "You cannot measure the acid or basic reaction of a water-soluble fertilizer by measuring the pH of the stock tank or the solution coming out of the end of the hose. Rather, it is the tendency of a water-soluble fertilizer to change medium-pH over time. Information on any bag of fertilizer will include the acid or basic reaction of a water-soluble fertilizer is written on the bag as an acidic or basic “calcium carbonate equivalency” (CCE), which is a relative measure of the tendency of the fertilizer to raise or lower medium-pH (Table 1). More importantly, the label tells the type and percentage of the different forms of nitrogen (ammonium, nitrate, or urea), as well as the percentage of the other nutrients contained in the fertilizer. In general, ammoniacal and urea nitrogen are acidic, and tend to drive the media pH down, whereas nitrate nitrogen is basic and tends to drive the media pH up."

It continues from there in that section, and moves on to 3 E. Irrigation water alkalinity. All of which backs up the original statement from Premier Tech. Neither biased nor wrong.

[The Blackmore Company sells fertilizer, among other things, just for the record. Do they want your plants to die because you haven't pH'd your nutes when using their product?]
For those that disagree with all of this may I suggest you obtain a basic Agronomy textbook. Here is one from the Internet Archive (it's public domain):
Textbook of Soil Science
by R. K. Mehra
This book will explain this stuff much more in-depth.
Personally I've gone to Kelp4Less nutes. They are reasonably priced (it's dry so you don't pay to ship water) easy to use and as long as your water is good (like my well) there is no need to pH.
 

Elvin

Well-Known Member
For those that disagree with all of this may I suggest you obtain a basic Agronomy textbook. Here is one from the Internet Archive (it's public domain):
Textbook of Soil Science
by R. K. Mehra
This book will explain this stuff much more in-depth.
Personally I've gone to Kelp4Less nutes. They are reasonably priced (it's dry so you don't pay to ship water) easy to use and as long as your water is good (like my well) there is no need to pH.
Page 226 is where soil buffering is first referenced but you'll likely need to skim through the previous pages to fully understand what is being presented.
 

DeeCee112

Plant of the Month: Mar 2020
Great thread, I'm a new Grower on my first indoor. My tap water comes out at 6.5PH which is the same as the Promix HP I'm using. I've been lowering to anywhere from 5.5 to 6 and honestly I'm just pretty lost on the whole PH thing and just trying to keep it in that range. I'm more concerned on dialing in everything else for now until I see any problems.

I grew 4 plants outside this summer in the ground in some home depot garden soil and besides lack of light they turned out great. Never measured PH.
 
Top Bottom