Phillip J Fry
Active Member
What nutes you using?
Constant Ph battle...
- Thread starter mr.lucky405
- Start date
Depending on your strain, your PH could be any where from 5.0 to 7.0. Your plant is gonna take the PH to where it's able to absorb the most from your mix. Mine are sitting at 6.5 right now, and has been as high as 6.8, all the while happy and healthy. Don't fight the rise, it's what the plant wants. Trust me, I went through this exact thing, go browse my grow.
Listen to Panhead, he knows what he's talking about.
woodsmaneh!
Well-Known Member
Careful what you read in some of these posts. For one we are dealing with hydroponics not dirt so a Ph of 7 will kill your plants or lock everything up and they still die. If you look at all the manufacture sites you will see they recommend 5.4 to 6.2 for hydro.
If your nutes are at 500ppm and two days later there at 350ppm you need to up your ppm! It works like this change res set ppm at say 600ppm ph 5.9 run for 24hrs, now if you ppm rise and ph drops nutes are to strong. If ppm drop and ph rises, nutes are to weak. But if your ppm and ph are basically stable then you have found the right mix for your plants.
[FONT="] Then when topping off your res use pre mixed nutes to keep it at that level, if it starts to rise or fall adjust top off nutes as needed to bring it back to proper level. This is how I set my system up and has worked great for me
[/FONT]
If your nutes are at 500ppm and two days later there at 350ppm you need to up your ppm! It works like this change res set ppm at say 600ppm ph 5.9 run for 24hrs, now if you ppm rise and ph drops nutes are to strong. If ppm drop and ph rises, nutes are to weak. But if your ppm and ph are basically stable then you have found the right mix for your plants.
[FONT="] Then when topping off your res use pre mixed nutes to keep it at that level, if it starts to rise or fall adjust top off nutes as needed to bring it back to proper level. This is how I set my system up and has worked great for me
[/FONT]
You and I both know that is just a made up number my friend.Careful what you read in some of these posts. For one we are dealing with hydroponics not dirt so a Ph of 7 will kill your plants or lock everything up and they still die. If you look at all the manufacture sites you will see they recommend 5.4 to 6.2 for hydro.
If your nutes are at 500ppm and two days later there at 350ppm you need to up your ppm! It works like this change res set ppm at say 600ppm ph 5.9 run for 24hrs, now if you ppm rise and ph drops nutes are to strong. If ppm drop and ph rises, nutes are to weak. But if your ppm and ph are basically stable then you have found the right mix for your plants.
[FONT="] Then when topping off your res use pre mixed nutes to keep it at that level, if it starts to rise or fall adjust top off nutes as needed to bring it back to proper level. This is how I set my system up and has worked great for me
[/FONT]View attachment 1771718
tommyo3000
Well-Known Member
People should be careful, you're right.Careful what you read in some of these posts. For one we are dealing with hydroponics not dirt so a Ph of 7 will kill your plants or lock everything up and they still die.
If your nutes are at 500ppm and two days later there at 350ppm you need to up your ppm! It works like this change res set ppm at say 600ppm ph 5.9 run for 24hrs, now if you ppm rise and ph drops nutes are to strong. If ppm drop and ph rises, nutes are to weak. But if your ppm and ph are basically stable then you have found the right mix for your plants.
[FONT="] Then when topping off your res use pre mixed nutes to keep it at that level, if it starts to rise or fall adjust top off nutes as needed to bring it back to proper level. This is how I set my system up and has worked great for me
[/FONT]View attachment 1771718
Your whole concept of PPM and pH fluctuation is all wrong, however.
PPM dropping does not necessarily raise the nutrient pH.
PPM rising does not necessarily lower the nutrient pH.
pH fluctuations occur for many reasons. It is not possible for most people to find some magic intersection of PPM and pH to keep both stable. Your personal pH and PPMs may be stable - I don't doubt that - but it is not because you found some ratio between the two. It has more to do with good nutrients, good make-up water. Consider yourself lucky.
There is so much more going on with water. For example, you could mix up a new batch of nutes, put them at 5.8pH and come back two hours later to have a pH of 8. This, as the artcile will explain to you below, happens if you have a bunch of dissolved CO2 or carbonic acid in your source water. I know this for a fact because my well is this way. It was a struggle to figure out why my water was super low or super high in pH at different times. Now I know to not adjust up EVER.. Especially when my source water goes through chemical changes that change the pH in mere hours.
Similarly, the alkalinity of the water has a HUGE effect on pH. And I don't mean acid/alkaline.. I mean total alkalinity, or carbonate content of the water. At pH below 8, the carbonates in your water are bi-carbonates or more precisely calcium bicarbonate (CaHCO3). The more of this that you have in your water, the more acid you have to dump in your reservoir to lower the pH. The pH will also rise alot even after you drop it down. This is the buffering effect of CAHCO3... It has nothing to do with the amount of nutrient plants are drinking..
Anyway, those are just two examples of why pH is so tricky.
If you want to read an article that touches on this stuff, check this out:
http://www.flairform.com/hints/water_quality.htm#Alkalinity (bicarbonate)
cheers
Phillip J Fry
Active Member
The plant changes the PH by absorbing and releasing compounds in the medium. So you saying that the plant eats up certain parts of the food just to get to a certain PH? If that is not how the plant changes the PH then how does it? If the plant does do this on its own then I am sure it is not running optimally when it has to adjust the PH through this process.
I think it is more likely that having the proper mix of food is the key to keeping PH in the right range. This way the plant absorbs and releases the chemical compounds in a more even manner keeping the PH more balanced.
The fact is if your food dont buffer the PH naturally like AN claims to then any changes in ppm are gonna effect your PH one way or the other. This is why I always suggest trying to balance the proper ppm with proper amount of water so the plants consume at the same rate helping balance everything.
Personally I dont worry about my PH in hydro as of right now and things seem great. I do use AN but it aint the PH perfect stuff.
*if this info I stated is not correct please feel free to explain why not.
Here is the science...not my words
When water reacts with itself to create the H3O(+)(hydroxyl) and OH(-) (hydroxide) species, one of the most fundamental and important characteristics of aqueous solutions is generated. The reactivity of a solution and its interaction with living organisms is determined in a great extent by the concentration of these two species, a variable usually measured as pH which is nothing but the negative value of the logarithm of the concentration of the H3O(+) ion. In hydroponic culture where our plants are in great contact with aqueous solutions the understanding of the role of the H3O(+) and OH(-) ions and their measurement as pH becomes very important if an in-depth understanding of what is going on wants to be attained. On todays post I will attempt to guide you into this micro world of pH and how and why pH changes within a hydroponic crop. What determines pH ? This variable is inversely proportional to the concentration of H3O(+) ions and directly proportional to OH(-) ions, the more hydroxil ions you have the more acidic your solution will be (the lower the pH) while more hydroxide ions will increase your pH and give you a higher pH reading. It is important to understand here that hydroxyl and hydroxide ions determine each others concentration. Since waters self-reaction equilibria must be maintained, the sum of pH and pOH must always be equal to 14 (a neat consequence of chemical equilibrium theory). When the concentration of hydroxyl and hydroxide ions is equal, pH and pOH contribute equally to the solution and they are therefore both 7, reason why the pH of a neutral solution has this value. Now that we know a little bit about pH we can understand better what happens when plants interact with a nutrient solution. When a plant is put within a given solution it wants to absorb the nutrients it needs to grow. These nutrients are available as ions that have a given charge. For example, nitrogen is absorbed as the nitrate ion (NO3(-)) while potassium is absorbed as the K(+) ion. When a plant takes potassium in, it deplets the solution of a positive charge. Since the solution must remain neutral the plant gives the solution an H3O(+) ion to compensate. The plant has therefore decreased the pH of the solution by absorbing a potassium ion. When nitrate is absorbed an ion with a negative charge- the plant does the opposite and exchanges the nitrate for an OH(-), the pH of the solution is increased.
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If plants absorbed nutrients in a perfectly symmetrical fashion, they would not increase or decrease pH as overall charge changes would be compensated. However as no one is perfect- plants absorb nutrients at different rates and they therefore create a pull towards a certain pH region. If a plant absorbs nitrate heavily it will start to contribute far more OH(-) than H3O(+) ions into the solution and the result will be a net increase in pH. Depending on the composition of the nutrients and the overall growth stage of the plant, different net movements in pH can be achieved by the plant.
The most influential factor in the changes of pH within a solution is generally the composition of the nitrogen component of the solution. When plants absorb ammonium ions NH4(+) they tend to decrease pH while nitrate as mentioned above tends to increase pH when absorbed. If you contribute a percentage of the nitrogen in your solution as ammonia the net effect will be a beneficial absorption pH buffer since plants will take nitrogen in both forms, effectively delaying the onset of important pH variations. Of course, the ratio of nutrients also performs a vital role since plants nutrient absorption mechanism are largely non-specific and they are greatly influenced by the different concentrations of nutrients within the solutions. Having a nutrient solution designed to provide an adequate balance will be vital in helping you control pH fluctuations.
When water reacts with itself to create the H3O(+)(hydroxyl) and OH(-) (hydroxide) species, one of the most fundamental and important characteristics of aqueous solutions is generated. The reactivity of a solution and its interaction with living organisms is determined in a great extent by the concentration of these two species, a variable usually measured as pH which is nothing but the negative value of the logarithm of the concentration of the H3O(+) ion. In hydroponic culture where our plants are in great contact with aqueous solutions the understanding of the role of the H3O(+) and OH(-) ions and their measurement as pH becomes very important if an in-depth understanding of what is going on wants to be attained. On todays post I will attempt to guide you into this micro world of pH and how and why pH changes within a hydroponic crop. What determines pH ? This variable is inversely proportional to the concentration of H3O(+) ions and directly proportional to OH(-) ions, the more hydroxil ions you have the more acidic your solution will be (the lower the pH) while more hydroxide ions will increase your pH and give you a higher pH reading. It is important to understand here that hydroxyl and hydroxide ions determine each others concentration. Since waters self-reaction equilibria must be maintained, the sum of pH and pOH must always be equal to 14 (a neat consequence of chemical equilibrium theory). When the concentration of hydroxyl and hydroxide ions is equal, pH and pOH contribute equally to the solution and they are therefore both 7, reason why the pH of a neutral solution has this value. Now that we know a little bit about pH we can understand better what happens when plants interact with a nutrient solution. When a plant is put within a given solution it wants to absorb the nutrients it needs to grow. These nutrients are available as ions that have a given charge. For example, nitrogen is absorbed as the nitrate ion (NO3(-)) while potassium is absorbed as the K(+) ion. When a plant takes potassium in, it deplets the solution of a positive charge. Since the solution must remain neutral the plant gives the solution an H3O(+) ion to compensate. The plant has therefore decreased the pH of the solution by absorbing a potassium ion. When nitrate is absorbed an ion with a negative charge- the plant does the opposite and exchanges the nitrate for an OH(-), the pH of the solution is increased.
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-If plants absorbed nutrients in a perfectly symmetrical fashion, they would not increase or decrease pH as overall charge changes would be compensated. However as no one is perfect- plants absorb nutrients at different rates and they therefore create a pull towards a certain pH region. If a plant absorbs nitrate heavily it will start to contribute far more OH(-) than H3O(+) ions into the solution and the result will be a net increase in pH. Depending on the composition of the nutrients and the overall growth stage of the plant, different net movements in pH can be achieved by the plant.
The most influential factor in the changes of pH within a solution is generally the composition of the nitrogen component of the solution. When plants absorb ammonium ions NH4(+) they tend to decrease pH while nitrate as mentioned above tends to increase pH when absorbed. If you contribute a percentage of the nitrogen in your solution as ammonia the net effect will be a beneficial absorption pH buffer since plants will take nitrogen in both forms, effectively delaying the onset of important pH variations. Of course, the ratio of nutrients also performs a vital role since plants nutrient absorption mechanism are largely non-specific and they are greatly influenced by the different concentrations of nutrients within the solutions. Having a nutrient solution designed to provide an adequate balance will be vital in helping you control pH fluctuations.
That article is what made me finally understand what was really happening, hope it helps you.
Phillip J Fry
Active Member
thats basically what i was saying was going on and have read that before. The plant dont eat nitrogen just to change the PH otherwise lockout would never happen cuz the plant wouldn't let it happen. The real key is in the sentence right after the picture.
"If plants absorbed nutrients in a perfectly symmetrical fashion, they would not increase or decrease pH as overall charge changes would be compensated. However – as no one is perfect- plants absorb nutrients at different rates and they therefore create a “pull” towards a certain pH region."
Now if your food is the wrong NPK mixture for the plants needs the PH will swing and may go out of range if no PH buffers are used.
"If plants absorbed nutrients in a perfectly symmetrical fashion, they would not increase or decrease pH as overall charge changes would be compensated. However – as no one is perfect- plants absorb nutrients at different rates and they therefore create a “pull” towards a certain pH region."
Now if your food is the wrong NPK mixture for the plants needs the PH will swing and may go out of range if no PH buffers are used.
My PH is sitting @ 6.5. I have a monitor for PPM measurement. What I find is that my PPM will climb then fall. Always staying in the same general area. To me that means it's consuming both water and nutes at the same rate. My plant releases ions to get to 6.5 every time I drop it, then it just sits, stable. Even been to 6.8, and sat there for awhile. Strange how someone said that would kill them. Finding the mix takes experience with your nutrients and grow system, lots of time, and a log book. Helps to be working with the same strain also. I use a 2 part nute called Flora Nova Grow and Bloom by GH, so my mix is kinda set in stone. A 3 part will give you more control.