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Drivejunky95
Well-Known Member
Am I correct in thinking there are stronger alternative pH down solutions? And could that help with water that climbs back to 8.5 pH?
And if true, an RO system vs pH down alternatives, would one be better for someone growing a few plants at a time?
Onto sciency stuffs -
I'm now getting the idea that there are three possible things that might be causing my changes in pH:
This is what I'm reading about buffering/watering CEC in coco and @TorturedSoul I think you were saying this:
"As the process commences, a high concentration of Ca molecules attaches to the media—as each Ca++ molecule is adsorbed, two molecules of K+ or Na+ are released because the Ca has a double-plus charge and K and Na are single-plus charges.
In the beginning, the exchange goes very quickly, but as the exchange continues, the concentration of the K and Na molecules released into the solution slows the exchange down and it will eventually come into equilibrium. The buffering process can be done in 10-15 minutes—the point at which the exchange slows down enough that the greater exchange is not worth the wait."
So the exchange comes into equilibrium and there's a higher overall concentration of Ca++? Buuuut that can't be the cause of the increase in pH runoff..... Cal/Mag water test pH went down....... or am I missing something?
Starting Tap Water w/ Cal/Mag: 8.5 pH
24hrs - 8.1 pH
48hrs - 8.0 pH
But what I thought was interesting was that the final nute solution test increased in pH, possibly because how nutrient elements interact with hydrogen over time? And this solution also includes elements like K which CEC also releases when Ca is added.
Starting Tap Water w/ Completed Nute Solution: 6.9 pH
24hrs - 7.5 pH
48hrs - 7.6 pH
72hrs - 7.7 pH
Again, the completed nute solution could have risen in pH because the tap water pH went up, but I did one more test today and it only went up 0.1, unlike the 0.6 pH increase in the very first 24hrs, indicating it could be close to it's final pH. It's still possible it could slowly climb back to the tap water's original pH of 8.5 or even higher I'm guessing.
I'm using the General Hydroponics Flora Series, mixed thoroughly in the correct order (Silica, Cal/Mag, Micro, Gro, Bloom, Diamond Nectar, Wetting Agent and lastly RapidStart).
The wetting agent is Coco-Wet aaaaaand ya... I just read on the bottle it's for foliar feeds.... whoops... could that be causing problems? It is 90% Modified Cocodiethanolamide and 10% inert constituents considered ineffective as an adjuvant
Anyway, when I first started feeding the runoff pH was pretty close or the same as the water put in. But over the course of about a week or so the runoff pH started going up higher than the water I was putting in. So I'm almost 100% certain something is happening in the CEC like increased concentrations of nutes to water AND/OR it's an accumulation/buffering affect of my 8.5 pH tap water slowly rising back to it's original pH over time.
I have an idea though...... if I buy an RO system and soak the coco in it for like a week or something (even though it's already pre-buffered, I don't actually know the starting pH of the medium) would that keep the CEC more or less manageable? I would use RO water of course while feeding... and I think if I just keep watering every 10 hours or so, I would be able to flush the old nutes out of the medium before they start mixing/reacting and up the pH again.
What do you think?
And if true, an RO system vs pH down alternatives, would one be better for someone growing a few plants at a time?
Onto sciency stuffs -
I'm now getting the idea that there are three possible things that might be causing my changes in pH:
- Tap water with high base pH
- Nutrient elements interacting with hydrogen molecules in water
- CEC
This is what I'm reading about buffering/watering CEC in coco and @TorturedSoul I think you were saying this:
"As the process commences, a high concentration of Ca molecules attaches to the media—as each Ca++ molecule is adsorbed, two molecules of K+ or Na+ are released because the Ca has a double-plus charge and K and Na are single-plus charges.
In the beginning, the exchange goes very quickly, but as the exchange continues, the concentration of the K and Na molecules released into the solution slows the exchange down and it will eventually come into equilibrium. The buffering process can be done in 10-15 minutes—the point at which the exchange slows down enough that the greater exchange is not worth the wait."
So the exchange comes into equilibrium and there's a higher overall concentration of Ca++? Buuuut that can't be the cause of the increase in pH runoff..... Cal/Mag water test pH went down....... or am I missing something?
Starting Tap Water w/ Cal/Mag: 8.5 pH
24hrs - 8.1 pH
48hrs - 8.0 pH
But what I thought was interesting was that the final nute solution test increased in pH, possibly because how nutrient elements interact with hydrogen over time? And this solution also includes elements like K which CEC also releases when Ca is added.
Starting Tap Water w/ Completed Nute Solution: 6.9 pH
24hrs - 7.5 pH
48hrs - 7.6 pH
72hrs - 7.7 pH
Again, the completed nute solution could have risen in pH because the tap water pH went up, but I did one more test today and it only went up 0.1, unlike the 0.6 pH increase in the very first 24hrs, indicating it could be close to it's final pH. It's still possible it could slowly climb back to the tap water's original pH of 8.5 or even higher I'm guessing.
I'm using the General Hydroponics Flora Series, mixed thoroughly in the correct order (Silica, Cal/Mag, Micro, Gro, Bloom, Diamond Nectar, Wetting Agent and lastly RapidStart).
The wetting agent is Coco-Wet aaaaaand ya... I just read on the bottle it's for foliar feeds.... whoops... could that be causing problems? It is 90% Modified Cocodiethanolamide and 10% inert constituents considered ineffective as an adjuvant
Anyway, when I first started feeding the runoff pH was pretty close or the same as the water put in. But over the course of about a week or so the runoff pH started going up higher than the water I was putting in. So I'm almost 100% certain something is happening in the CEC like increased concentrations of nutes to water AND/OR it's an accumulation/buffering affect of my 8.5 pH tap water slowly rising back to it's original pH over time.
I have an idea though...... if I buy an RO system and soak the coco in it for like a week or something (even though it's already pre-buffered, I don't actually know the starting pH of the medium) would that keep the CEC more or less manageable? I would use RO water of course while feeding... and I think if I just keep watering every 10 hours or so, I would be able to flush the old nutes out of the medium before they start mixing/reacting and up the pH again.
What do you think?
