pH: Constant or Fluctuating, Which Is Better?

[TheGreenReaper]

Hey IC Mag family. I have a thread going about the various opinions and discrepancies on pH meters vs. Strips and some ideas have come up that we dont want to continue discussing as it will derail the thread. http://www.icmag.com/ic/showthread.php?t=160081

A few of us want to have the discussion as to which is better: Constant pH throughout a grow, or some type of either systematic or random fluctuation for different nutrient uptake.

There are numerous opinions and experiences with this one. This is one of those aspects of growing like religion...everyone has a different take. I think as growers we can all agree pH is important, and to neglect it indicates either extreme luck, extreme ignorance, or extreme expertise in the case of the masters of buffered soil. In addition, water quality has an effect upon pH. Heck, the inhibition of the potential uptake of nutrients at the proper pH due to things like calcium binding to other elements is possible even if you try to get the pH "right".

In my experience, when I have tried a dynamic pH regiment as opposed to a static regiment, I get problems. They problems show up 3-5 days after h20/feed. I start to get the spotty leaves, then the unhappy plant, etc. Grow enough and you can tell in 4 seconds whether or not the plant is happy even if "visible" damage is not yet evident. Am I alone in this or do others agree?

I have found better results, after years of fiddling with it, to start at 5.8 at clone, run 5.8 till about week 6 of flower. Then go 5.9 week 7, then 6 for weeks 8&9. I have found a little better flush by rising slightly at the end (I guess I am pulling some things out of the media that were lightly inaccessible (locked) at the 5.8 range.)

I do understand the role media will play in this discussion. The buffering capabilities of hydro are much less than say...soil. I personally grow in 100% unamended Coco. I apply within 30 min of mixing a batch, so the plants receive a pH of what I give them at the time. I used to measure run off, but dont anymore...I dont know, you just get where you dont need to...you can tell what is going on. In addition, I have a pretty basic and dialed nute regiment so I am not recreating the wheel often.

So, lets hear all about the different results and reasons for your pH method of choice. Lets even explore things like the chelating abilities of humics, the outlier properties of coco in its CEC properties, the ease with which hydro naturally fluxes due to aeration and nute usage, etc. Please keep it clean and civil, again pH is like religion, no right answer...but if it works for you...then it works for you..period.

Let the games begin!

 

[TheGreenReaper]

bump

...for those voting, why do you do what you do?

 

[tokinafaty420]

I let mine drift a bit because at certain pH levels different nutrients become more available.

 

[supermanlives]

i quit checking.

 

[Admiral Canna]

For those that do fluctuate, I would like to know if you have a science to it, or are you being lazy?

I would like to get into the science side of the convos...not "I quit checking"...thats a useless post...no offense.



I keep my pH between 6.4-6.5 and I grow in soil. But I have heard people speak of the flux. Kinda like switching yer nutes from grow to bloom......

Hope some others join in as well.

 

[Carboy]

I would like to get into the science side of the convos...not "I quit checking"...thats a useless post...no offense.

Not really. One of the choices could have been. "Can't count the number of times a PH pen bit me in the ass."
Not my opinion, but valid nonetheless.
CB

 

[pray4pistils]

I keep it consistant. When you fluctuate your pH you might make certain elements more available, but you also lock certain things out.

Sure, but that's true no matter what pH you keep. By locking it in you're guaranteed to make something unavailable (and to KEEP it unavailable). Allowing it to drift within an acceptable range (e.g. 5.5 - 6.1) is the key to getting everything you need.

It also means that you're adding less chemical to "correct" the solution. This always saves money. In the case of pH down, a large amount of phosphoric acid in the water promotes brown slime algae. With pH up, too much can lock out magnesium and boron.

 

[Hydro-Soil]

In my experience, when I have tried a dynamic pH regiment as opposed to a static regiment, I get problems. They problems show up 3-5 days after h20/feed. I start to get the spotty leaves, then the unhappy plant, etc. Grow enough and you can tell in 4 seconds whether or not the plant is happy even if "visible" damage is not yet evident. Am I alone in this or do others agree?

I have found better results, after years of fiddling with it, to start at 5.8 at clone, run 5.8 till about week 6 of flower. Then go 5.9 week 7, then 6 for weeks 8&9. I have found a little better flush by rising slightly at the end (I guess I am pulling some things out of the media that were lightly inaccessible (locked) at the 5.8 range.)

Dynamic pH seems to take a bit of adjustment, for each setup/style. The main error I see you making is not starting at a low enough pH.

Start at approximately 5.2... a week before 12/12 or so. Essentially you want your pH to be hitting 6.1... right about the time you're 15-20 days into flower... depending on the strain. Let it sit there for about 2 weeks and then drop it down to 5.2 again.

Since the plant is able to absorb different elements at different rates at different pH ranges.... it makes sense to allow the plant access to all of the best pH ranges. The reason your plants start spotting right away.... is they haven't had a chance to stock up on the elements they need during the beginning of flower.

Plants don't suck up nutes and use them right away. Some elements are slower than others and take more time to build up, so having them in the system of the plant before flower, helps significantly. (Calcium and Mag deficiencies anyone?)

Like anything... it takes a bit of work but the payoff is great.

Stay Safe!

 

[TheGreenReaper]

Hello and thanks to everyone reading, voting, and contributing to the thread.

This is some great conversation so far, especially the nice detail posted above by Hydro...I would love to hear more and hope more people add their opinion and vote.

Onward.

 

[FreezerBoy]

I keep it consistant. When you fluctuate your pH you might make certain elements more available, but you also lock certain things out.

Fluctuating prevents lockup. Consistency causes lockup. No one reading allows absorption of all nutes. A small swing over a couple of weeks is good for you.

 

[Carl Carlson]

the answer totally depends on the medium