Do we need to pH adjust our nutrient solutions?

[Peat Phreak]

well, its because professional agriculture pratically doesnt care for pH.

No professional grower (that has a minimum of knowledge of the medium and his water source) invest time and money regulating pH of a low alkalinity water.

But a professional grower will obviously monitor its medium pH and interact with it as needed.

You said in your own phrase: "common way to reduce alkalinity is lowering pH". But see, your focus is not pH, is reducing alkalinity.

They certainly do pay attention to pH when the water has high alkalinity. Do you think they just open up the acid injector and inject whatever amount comes out? No, they inject a carefully measured dose of acid. Because pH matters.

 

[InTheShed]

A ph'd feed can force a poorly balanced alkaline'd medium to work for us (coco, peat). It can also work to change the mediums alkalinity over time.

A pH'd feed is a good idea in coco - indeed it's recommended - but in buffered media is has no effect on the ability of your plant to uptake nutes.

And the way to change the pH of your buffered medium is either changing the type of nitrogen for 2 weeks or using something to quickly lower or raise pH of the medium, such as lime or sulfur.

Those two methods are not used on an ongoing basis, and only used when a test of the substrate pH shows it has gone out of the correct range.

They certainly do pay attention to pH when the water has high alkalinity. Do you think they just open up the acid injector and inject whatever amount comes out? No, they inject a carefully measured dose of acid. Because pH matters.

They pay attention to the pH of their soil and correct it when it's out of range, not on an ongoing basis.

Substrate pH matters not water pH.

 

[Peat Phreak]

As I might have mentioned, the pH of your nutes doesn't matter in a buffered medium, but the alkalinity can. If you have high alkaline water, you deal with it when the pH of your substrate drifts beyond the acceptable range for cannabis, and there are a few ways to do it when it happens. One of the ways to deal with a medium whose pH is too high is to acidify the medium, which can be done with sulfuric acid though that's not the recommended way according to the folks who make ProMix.

Thanks bruno!

So I can drop a quart of 5M acid in a 5 gallon pot with every watering and things will turn out fine?

 

[InTheShed]

So I can drop a quart of 5M acid in a 5 gallon pot with every watering and things will turn out fine?

Exactly the opposite of what I said. If you need to bring an out-of-range medium into range using sulfuric acid (not hydrochloric) it would be once maybe twice.

No one is saying to add acid to your nutes every time you water.

If you're just being obnoxious and sarcastic and asking if it's okay to feed you plants with pH 2 water then the answer is no, but that describes no one.

But as I mentioned earlier, someone here did a high/low nute pH on their plants and found no difference.

 

[Peat Phreak]

This is info from U of NC regarding how to reduce media pH in soilless media:​

​

Acid Water Drench​

Some growers use this intermediate correction when pH levels are not excessively high and a quick lowering of substrate pH is desired. Sulfuric acid is recommended to acidify irrigation water to a pH 4.0 to 4.5. Apply this acid water as a substrate drench, providing 5 percent to 10 percent excessive leaching of the substrate. Rinse the foliage to avoid phytotoxicity. Results should be visible within five days. Retest the substrate pH and repeat if needed.

Sure seems like pH of the feed matters here, boss. Regardless of how many times you type it doesn't.

This source is also a good read on the general topic

StackPath

 

[InTheShed]

Sure seems like pH of the feed matters here, boss. Regardless of how many times you type it doesn't.

Doesn't look like you read what you posted.

That was one application on a substrate that is already drifting out of range. One application, wait 5 days, retest if needed.

That's not pH adjusting your nutes every time you water.

 

[Peat Phreak]

Doesn't look like you read what you posted.

That was one application on a substrate that is already drifting out of range. One application, wait 5 days, retest if needed.

That's not pH adjusting your nutes every time you water.

Comments like this are not productive. You have made a LOT of false assumptions about me and my education ITT.

I completely read and understood what I posted. But it appears you don't see how what I posted refutes your main assertion of pH not mattering.

Input pH, can directly influence media pH in the near term or over time according to the University of North Carolina, not me. So pH matters.

It's okay to be wrong on the internet, dude.

 

[InTheShed]

Comments like this are not productive. You have made a LOT of false assumptions about me and my education ITT.

I never made any false assumptions about you or your education, and what's not productive is sarcastic posts and referring to people as "boss."

Sounds like you're taking this personally. Please don't.

Input pH, can directly influence media pH in the near term or over time according to the University of North Carolina, not me. So pH matters.

Acidifying your soil to fix a drift in substrate pH is not the same as pH adjusting your nutes when you water.

UNC doesn't recommend pH adjusting nutes anywhere in what you posted, and the opening post in this thread explains why. They are giving instructions on how to fix pH issues in the substrate.

Feel free to add sulfuric acid to your plants every time you water, but before you recommend it to others check with the folks who make Sunshine Mix to see if they recommend it.

pH adjusting your nutes is not needed in a buffered medium, but fixing the pH of the medium may be necessary if it drifts out of acceptable range. As I have stated, sulfuric acid is just one of the ways to do it, and not the way I'd recommend.

 

[Chuckeye]

Well water @ 500 ppm, ph at 7.5 last time I checked !

No ph down, feed is MC. Currently @ 6.5g/4L with a ppm of 1000, 3 gallon fabric pots with ProMix HP.

Double Chocolate, day 91, 41 days of 12/12.

Cheers

 

[InTheShed]

Well water @ 500 ppm, ph at 7.5 last time I checked !
No ph down, feed is MC. Currently @ 6.5g/4L with a ppm of 1000, 3 gallon fabric pots with ProMix HP.
Double Chocolate, day 91, 41 days of 12/12.
Cheers

That's quite a looker Chuckeye, and all that in a 3 gallon pot!

 

[Chuckeye]

That's quite a looker Chuckeye, and all that in a 3 gallon pot!

Thanks @InTheShed !

That's as big a pot as I want to deal with, watering and harvest wise

Buffered medium, buffered nutrients and wet/dry cycle.

Actually I believe MC uses the word "chelated" .

First auto grow was in a 2 gallon plastic pot with AN nutrients, 13.2 oz !

Early Miss from Crop Kings of all places

From my last auto grow, this is a Gorilla Glue #4 from autoflower dot ca.

11g short of a pound !

I Do Not Miss messing with acid, Thank you very much

Cheers, eh ?

 

[Diatomacious]

So there is no study that you can provide proving the pH of the feed is somehow irrelevant.

You can do this at home. Check the pH of the peat, water with fertilizer of known pH and recheck the pH of the medium. 1/2 to 1 1/2 oz of lime per gallon of peat is what ProMix website claims is necessary to obtain the correct pH in peat moss, that is way more than what you end up with in the nutrient solution even if you correct for the acidity of the fertilizer.

 

[Diatomacious]

I've tried to correct soil pH with nutrient solution and ended up just mixing soils of different pH to obtain the pH I was after. It would take months of watering to change the pH of the soil just a little bit.

 

[InTheShed]

Thanks @InTheShed !
That's as big a pot as I want to deal with, watering and harvest wise
Buffered medium, buffered nutrients and wet/dry cycle.
Actually I believe MC uses the word "chelated" .
First auto grow was in a 2 gallon plastic pot with AN nutrients, 13.2 oz !
Early Miss from Crop Kings of all places
From my last auto grow, this is a Gorilla Glue #4 from autoflower dot ca.
11g short of a pound !
I Do Not Miss messing with acid, Thank you very much
Cheers, eh ?

Cheers for sure! Just to clarify, check the label on any synthetic nute with micronutrients and those elements will be chelated. Otherwise the plants can't absorb them.

MC's difference is that they used amino acids rather the EDTA, which some individuals find troubling for environmental reasons. Also, amino acid chelation has been shown to increase rice yields over EDTA. @farside05 did a great post on chelated nutes here.

I've tried to correct soil pH with nutrient solution and ended up just mixing soils of different pH to obtain the pH I was after. It would take months of watering to change the pH of the soil just a little bit.

I've increased the pH of my ProMix by over a point running high nitrate fertilzer, and lowered it back in range in two weeks using nutes that had more ammoniacal nitrogen. But my grows are longer in one pot than most, with harvest close to 6 months or more from sprout. It's the main reason I went back to soil, which has a much greater pH buffering capacity.

 

[KeithLemon]

Comments like this are not productive. You have made a LOT of false assumptions about me and my education ITT.

I completely read and understood what I posted. But it appears you don't see how what I posted refutes your main assertion of pH not mattering.

Input pH, can directly influence media pH in the near term or over time according to the University of North Carolina, not me. So pH matters.

It's okay to be wrong on the internet, dude.

Advise is free and you can do what you want with it. Just a thought.

 

[Diatomacious]

check the label on any synthetic nute with micronutrients and those elements will be chelated

Just for clarification... the chelation in those nutes is necessary to maintain solubility. Sulfates are just as good as chelates (better in my opinion since no EDTA DTPA...) but will not stay soluble at higher concentrations. Fertilizers companies only use it so they can put 100 gallons of solution in a 1 liter bottle.

I've increased the pH of my ProMix by over a point running high nitrate fertilzer, and lowered it back in range in two weeks using nutes that had more ammoniacal nitrogen.

I'd have to see it to believe it as this is contradictory to what I have experienced personally. Just be careful with the ammonia nitrogen. It is what is polluting the ocean and causing global warming. It kills phytoplankton and diatoms (single celled organisms that produce oxygen for the earth) almost instantaneously. This has been going on since the hole in the ozone started appearing and the government made us switch from r12 to r134a. Did absolutely no good as the ozone hole is just getting bigger. Dump it in the soil if you must as this gives soil microbes a chance to neutralize the ammonia before it runs into rivers and streams that empty into the ocean.

Stick your finger in fertilizer that contains ammonia if you do not believe me. You'll end up washing it off in a couple minutes as it absorbs into the skin of your finger and you feel what ammonia does to aquatic life.

 

[InTheShed]

Just for clarification... the chelation in those nutes is necessary to maintain solubility. Sulfates are just as good as chelates (better in my opinion since no EDTA DTPA...) but will not stay soluble at higher concentrations. Fertilizers companies only use it so they can put 100 gallons of solution in a 1 liter bottle.

"Chelation keeps a micronutrient from undesirable reactions in solution and soil. The chelated fertilizer improves the bioavailability of micronutrients such as Fe, Cu, Mn, and Zn"
Source

Not only solubility, availability as well.

Beyond that, higher concentrations in the same bottle means less weight per pound of mixed nutrients, saving gas (and CO2 emissions) when shipping as well as lowering the amount of plastic needed.

Sulfate-based nutes can throw off the sulfur ratios in nutrient blends depending on their makeup. For example, magnesium sulfate alone is only 10ppm of magnesium but 13ppm of sulfate. That adds up very quickly.

I'd have to see it to believe it as this is contradictory to what I have experienced personally.

I have many experiences with the short buffering ability of ProMix during the 3+ years I grew with it and the many conversations I've had with their soil scientist about it.

They recommend switching from a nearly all nitrate nitrogen source to an 80/20 nitrate/ammoniacal blend to lower the pH over the course of 14 days. It works. I've offered the same advice to others having similar pH rise from nitrate nutes and they have brought theirs into range using the same technique.

Stick your finger in fertilizer that contains ammonia if you do not believe me. You'll end up washing it off in a couple minutes as it absorbs into the skin of your finger and you feel what ammonia does to aquatic life.

I have no idea what ammonia does to aquatic life but I'm sure it's not good. I'm not applying it to open fields with runoff into waterways, so I feel okay about using it when I need to!

 

[dr.h00k]

...I would hazard to guess, that 80 to 90 percent of forum members here are "hobby growers", for their own personal use...my advice is K.I.S.S, and don't get too caught up in the science/hype, as it's a rabbit hole, with a lot of tunnels, that can leave some just chasing their tails...light, nutrients and environment are the basics...as an always soil grower, from Miracle Gro. to Organic,, I've never owned a Ph pen(but have some litmus paper on hand for a slurry test, if I think something is amiss) and have had many successful grows, and some less than anticipated...such is life, just like what happens naturally outdoors...JMO...cheerz... ...h00k......

 

[Diatomacious]

I have no idea what ammonia does to aquatic life but I'm sure it's not good. I'm not applying it to open fields with runoff into waterways, so I feel okay about using it when I need to!

Ammonia nitrogen contamination in our food supply is why you see so many adult diaper commercials on TV. It is poisonous even in trace amounts. Anyone who tells you it is safe to eat and smoke is lying. This is from personal experience growing my own. Nitrate nitrogen will not give this effect.

 

[KeithLemon]

Ammonia nitrogen contamination in our food supply is why you see so many adult diaper commercials on TV. It is poisonous even in trace amounts. Anyone who tells you it is safe to eat and smoke is lying. This is from personal experience growing my own. Nitrate nitrogen will not give this effect.

Sounds like bad shit and should be banned.