Water Chemistry and PH raise.

Impregnant

Active Member
Hello everyone.
I just dived into hydroponics... and I'm already drowning... o_O
Well, i have 8 plants in two box + a third maintenance box for a total volume of 70L.
Roots are not submerged as i use 360degrees sprinklers. It is may be called Aero..


Here is my problem:
I use RO water which is EC 0.0 PH~4
I put my MaxiGrow nutrients and my PH goes down to 3.5.
So i want to raise it and i use a powder, because i dont have the regular PH UP.
This is the powder that i use with the same RO water to put in my aquariums. This is specially designed for soft water shrimps. I know by experience that it buffs the PH.

It is called GH+/KH+ and here is the composition:

Cations
7,05% Sodium
2,61% Potassium
13,89% Calcium
5,39% Magnesium
0,02% Strontium

Anions
1,30% Carbonate
18,72% hydrocarbonate
32,62% Chloride
16,91% Sulfate
0,00% Phosphate

0,35492% Trace elements

Rest hydration


I've raised my PH to 5.7 last night with this. This morning it was already 6.5....
Ok, i've put some regular PH down from GHE to 5.8. Two hours later it was 6.4....

Does someone have an idea for me? I should not use this powder for any reasons?
 

Renfro

Well-Known Member
Your RO should NOT be a pH of 4. Something's wrong there.
You can't really get a good reading on RO because nothing is in it. It should be 7.0 and a test strip or drops is the best way to ensure that is the case but really if it's 0 - 3 PPM RO water then it's 7.0 pH.
 

Renfro

Well-Known Member
Do NOT adjust the pH of RO water until AFTER nutrients are added. You should AT LEAST be adding cal mag to RO water to replace the stripped minerals.
 

Airwalker16

Well-Known Member
Do NOT adjust the pH of RO water until AFTER nutrients are added. You should AT LEAST be adding cal mag to RO water to replace the stripped minerals.
That's what I was going to also add. CalMag is absolutely essential if using RO. CaliMagic just does such a good job :) luuuuuh dat shiiiii
 

Impregnant

Active Member
Your RO should NOT be a pH of 4. Something's wrong there.
Hum OK...

You can't really get a good reading on RO because nothing is in it. It should be 7.0 and a test strip or drops is the best way to ensure that is the case but really if it's 0 - 3 PPM RO water then it's 7.0 pH.
Ok i did it. Nothing in range. Definetly not PH7. PH4 neither i agree.
phdrop.jpg
I keep freshwater shrimps. They like acidic water. Ph 5.5
I know a little bit about ph and a EC 0 doesnt give a PH 7 at all.
When you remove everything from the water, your KH=0 and your GH=0. The only way to lower the PH is to lower the KH.
The carbonate hardness is what buffers the PH.

Do NOT adjust the pH of RO water until AFTER nutrients are added. You should AT LEAST be adding cal mag to RO water to replace the stripped minerals.
I adjusted my PH to my RO water, after dosing my nutrients. When i put my MaxiGrow in my RO water, ph goes down to 3.8.
That is what my powder do, it is adding cal/mag, and that why it raises the PH.
13,89% Calcium
5,39% Magnesium


Yeah I don't trust that meter, wonder what one it is?
This is HANNA ph meter and it is fully calibrated. I use it for my aquariums. Have no experience with hydroponics but a good one in aquariums. And my meter is allright with my other liquids.
 
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Renfro

Well-Known Member
This seems like it would be applicable.

The pH of pure water (H20) is 7 at 25oC, but when exposed to the carbon dioxide in the atmosphere this equilibrium results in a pH of approximately 5.2.
 

Renfro

Well-Known Member
This is HANNA ph meter and it is fully calibrated. I use it for my aquariums. Have no experience with hydroponics but a good one in aquariums. And my meter is allright with my other liquids.
Iv'e extensively used their old HI98129 combo back in the day, it was a good meter for a while but then probe quality dropped to shit, probably old stock. I had probes on those last for several years being stored in much less than ideal conditions lol. I didn't know about pH probe maintenance back then but they still lasted. I just made sure the cap was on with some nutes or tap water in there, I wasn't using the KCl storage solution.

Anyways, if your pH is getting way too low you will need a good pH up buffer, trying to use bullshit here will just result in fighting it a lot more. I prefer advanced pH buffers because they are about 10x more concentrated than GH, but GH is the same stuff and measurements are more forgiving but you go through it faster.
 

Larry3215

Well-Known Member
This is a cut/paste from a reply I made to someone else:

There are several different things that can cause drastic PH increases. These are in no particular order.

1) Biological action. It could be from algae, or other bacterial growths in your rez, or in the buckets. As far as I know the only solution for this is to use IN-organic nutes with absolutely NO ingredients derived from anything organic or plant based. Something like Jacks 321 hydro will work great, but be careful if you use any cal/mag, or other additives that have ANYTHING derived from plant material.

I had this exact problem when I was using Advanced Nutes PH perfect line, Mega Crop, and Fox Farm nutes. Once I switched to Jacks321, that all went away and I was able to reduce the chlorine I add to next to nothing. My rez stays fresh for up to 9 days between refills. I am drain to waste in an AAA setup, so no root exudates to worry about. See #2.

2) It could also be from the roots interacting with the solution, but that is dependent on your EC level to some degree, but if you have bad bacterial growths, your screwed.

Bottom line - do not ever use anything organic in hydro.

3) The calcium/alkalinity of your water is the next one. Every time you PH down, the dissolved C02 level increases, which lowers the PH by the formation of carbonic acid. Unfortunately, when you aerate, the excess C02 in the water leaves the solution, which lowers the concentration of carbonic acid, which raises the PH.

The more you aerate, the faster the PH goes up. The worse your calcium problem is, the higher it will go. Basically, your water has what I think of as a 'natural' or preferred PH level once every thing equalizes - dissolved C02 mainly. When you PH down, then aerate, it wants to go back to that PH. How bad this is depends on your water, but if its well water, there is an excellent chance you have this problem to some degree.

4) The other thing is temperature. I just confirmed this recently in my grow. I try to keep my rez water around 65F as a max, but that water feeds down to a small holding tank that is about 1 liter. That small tank is used to adjust the water level for the AAA nozzles to siphon from, so it has to be near the root chamber. That area where the tank sits varies from the hi 70's to the hi 80's temperature wise because I have to heat my root chamber or it stays too cold. So that water in the tank varies from the upper 70's to mid 80's, while my rez stays at no more than 65F and often down to 55F when I do a rez refill or add ice to keep it cool.

Here is where the problem arises. The dissolved C02 level goes DOWN when temperature increases, and goes UP when temperature decreases.

Remember the dissolved C02 forms carbonic acid which is what lowers the PH. So, any time there is a temperature change, the carbonic acid level changes which changes your PH. In my case, when the rez temp is near 65F and the siphon tank is down near 75 F, the PH goes up by about 0.1. When the rez is cold at 55F and the siphon tank is at 85F, the PH difference will be 0.3 to 0.4. So when I was setting my rez to 5.8, my roots were being sprayed at 5.9 to 6.2 PH.

Keeping your water temps higher means your PH will want to stay higher. Keeping your water temps lower means your PH will want to stay lower.

I have been fighting all these issues for two years trying to sort out why my PH was impossible to control. It turns out I have all of them. My solutions were as follows.

1) Never ever ever ever ever use anything organic in the rez - ever. Bacteria and algae just love that crap and they grow like mad when its available. By the way - this very much includes any so called "beneficial bacteria". Dont use it. I also am absolutely fanatical about light discipline as far as light getting into the rez, any fitting, and all tubing. Algae wont grow if there is zero light, but you must check all fittings, and pipes, buckets, lids etc.

2) I dont have to worry about my roots messing up the PH because they never touch the rez water and there is no re-circulation. I run drain to waste. Once the roots get sprayed, the runnoff get tossed out. In your case, as long as the EC is close, that should be easily manageable.

3)My alkalinity/calcium problem isnt too extreme, but it is there. My well water likes to be at around 6.4-6.5 PH after it equalizes at my tipical room temp = 68-70F. I handle that by doing the minimum amount of aeration I can get by with in the rez. Plus, I keep the rez remps low - below 65. I use an aquarium pump in my rez to keep it stirred up and it flumes the water surface. It also has an air line that sucks in air and puts out small bubbles when the pump runs. I only run the pump 1 minute out of every 20. Just enough to be sure no anerobic bacteria can get started. I get all the aeration I need by the air atomization from the spray nozzles, and the micron sized droplets. You wont want to keep your water as cold as I do - submerged roots wont like it. 68-70 is probably the ideal range for your situation.

Hope that helps, and good luck!!!
 

Impregnant

Active Member
Iv'e extensively used their old HI98129 combo back in the day, it was a good meter for a while but then probe quality dropped to shit, probably old stock. I had probes on those last for several years being stored in much less than ideal conditions lol. I didn't know about pH probe maintenance back then but they still lasted. I just made sure the cap was on with some nutes or tap water in there, I wasn't using the KCl storage solution.

Anyways, if your pH is getting way too low you will need a good pH up buffer, trying to use bullshit here will just result in fighting it a lot more. I prefer advanced pH buffers because they are about 10x more concentrated than GH, but GH is the same stuff and measurements are more forgiving but you go through it faster.
I will get the regular PH UP. But with all of this shit going around nowadays, it is hard to be delivered fast.
You can also use Potassium Hydroxide as a PH UP. But i will buy the one which is 10times the prices, just to be like everybody.

Have another question here: I did use PH Down from GHE to lower my PH. (By the way, why you in the US use to say GH?)
On the PH UP from GHE, liquid version, it says:
"thanks to its nitric and phosphoric acid as well as its organic adjusters. " then:
Contents:
  • Nitric Acid
  • Phosphoric Acid
  • Organic regulators
I've been adviced not to add anything organic to Hydroponic. I can understand that, but what if the PH DOWN contains organic matter...
 

Impregnant

Active Member
This is a cut/paste from a reply I made to someone else:

There are several different things that can cause drastic PH increases. These are in no particular order.

1) Biological action. It could be from algae, or other bacterial growths in your rez, or in the buckets. As far as I know the only solution for this is to use IN-organic nutes with absolutely NO ingredients derived from anything organic or plant based. Something like Jacks 321 hydro will work great, but be careful if you use any cal/mag, or other additives that have ANYTHING derived from plant material.

I had this exact problem when I was using Advanced Nutes PH perfect line, Mega Crop, and Fox Farm nutes. Once I switched to Jacks321, that all went away and I was able to reduce the chlorine I add to next to nothing. My rez stays fresh for up to 9 days between refills. I am drain to waste in an AAA setup, so no root exudates to worry about. See #2.

2) It could also be from the roots interacting with the solution, but that is dependent on your EC level to some degree, but if you have bad bacterial growths, your screwed.

Bottom line - do not ever use anything organic in hydro.

3) The calcium/alkalinity of your water is the next one. Every time you PH down, the dissolved C02 level increases, which lowers the PH by the formation of carbonic acid. Unfortunately, when you aerate, the excess C02 in the water leaves the solution, which lowers the concentration of carbonic acid, which raises the PH.

The more you aerate, the faster the PH goes up. The worse your calcium problem is, the higher it will go. Basically, your water has what I think of as a 'natural' or preferred PH level once every thing equalizes - dissolved C02 mainly. When you PH down, then aerate, it wants to go back to that PH. How bad this is depends on your water, but if its well water, there is an excellent chance you have this problem to some degree.

4) The other thing is temperature. I just confirmed this recently in my grow. I try to keep my rez water around 65F as a max, but that water feeds down to a small holding tank that is about 1 liter. That small tank is used to adjust the water level for the AAA nozzles to siphon from, so it has to be near the root chamber. That area where the tank sits varies from the hi 70's to the hi 80's temperature wise because I have to heat my root chamber or it stays too cold. So that water in the tank varies from the upper 70's to mid 80's, while my rez stays at no more than 65F and often down to 55F when I do a rez refill or add ice to keep it cool.

Here is where the problem arises. The dissolved C02 level goes DOWN when temperature increases, and goes UP when temperature decreases.

Remember the dissolved C02 forms carbonic acid which is what lowers the PH. So, any time there is a temperature change, the carbonic acid level changes which changes your PH. In my case, when the rez temp is near 65F and the siphon tank is down near 75 F, the PH goes up by about 0.1. When the rez is cold at 55F and the siphon tank is at 85F, the PH difference will be 0.3 to 0.4. So when I was setting my rez to 5.8, my roots were being sprayed at 5.9 to 6.2 PH.

Keeping your water temps higher means your PH will want to stay higher. Keeping your water temps lower means your PH will want to stay lower.

I have been fighting all these issues for two years trying to sort out why my PH was impossible to control. It turns out I have all of them. My solutions were as follows.

1) Never ever ever ever ever use anything organic in the rez - ever. Bacteria and algae just love that crap and they grow like mad when its available. By the way - this very much includes any so called "beneficial bacteria". Dont use it. I also am absolutely fanatical about light discipline as far as light getting into the rez, any fitting, and all tubing. Algae wont grow if there is zero light, but you must check all fittings, and pipes, buckets, lids etc.

2) I dont have to worry about my roots messing up the PH because they never touch the rez water and there is no re-circulation. I run drain to waste. Once the roots get sprayed, the runnoff get tossed out. In your case, as long as the EC is close, that should be easily manageable.

3)My alkalinity/calcium problem isnt too extreme, but it is there. My well water likes to be at around 6.4-6.5 PH after it equalizes at my tipical room temp = 68-70F. I handle that by doing the minimum amount of aeration I can get by with in the rez. Plus, I keep the rez remps low - below 65. I use an aquarium pump in my rez to keep it stirred up and it flumes the water surface. It also has an air line that sucks in air and puts out small bubbles when the pump runs. I only run the pump 1 minute out of every 20. Just enough to be sure no anerobic bacteria can get started. I get all the aeration I need by the air atomization from the spray nozzles, and the micron sized droplets. You wont want to keep your water as cold as I do - submerged roots wont like it. 68-70 is probably the ideal range for your situation.

Hope that helps, and good luck!!!
Yes, that is where i got:
Bottom line - do not ever use anything organic in hydro.

hence my question:
Ph Down contains orgnanic matters?
 

Larry3215

Well-Known Member
Yes, that is where i got:
Bottom line - do not ever use anything organic in hydro.

hence my question:
Ph Down contains orgnanic matters?
Then chose a different PH down. You can use pure sulfuric (battery acid) or phosphoric. You dont need any regulators, and you certainly dont want anything organic in it.

I used plain old battery acid for years. Buy a container at an auto parts store for about $8. Add 1 cup of acid to 1 gallon of water and you are good to go. I dropped down to 1/2 cup/gallon after I got my PH issues under control. Phosphoric works great too. I ran out of battery acid and decided to try some phosphoric. Bought a qt from Amazon. I forget the ratio Im using now - maybe 1/3 cup to 1 gallon. One gallon lasts me a looong time.

EDIT: NEVER add water to acid. ALWAYS poor the acid into the water. Never the other way around. If you poor water into acid, it can super heat and blast acid all over the place. Also - wear old cloths, gloves, and eye protection. :)
 
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Larry3215

Well-Known Member
The more i search and the more i think that it is the 7,05% Sodium who can be a problem in my water...
Wow. You on a water softener system? Thats twice as much salt as in the ocean!

Your plants are not going to like that much salt.

Wait - I thought you started with RO water? RO should take all that salt out if its working properly.

Sodium Chloride wont effect PH, so I dont see why that would be an issue - other than killing the plant :)

EDIT: Potassium Hydroxide is fine. Its a LOT cheaper than commercial PH down. Thats what I have used for years.
 
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