Does PH drift in short period storage?

Slim Pickens

Slim Pickens

I Blue my mind.
I am noticing that my PH'd water drifts higher when I don't use it promptly. Is this normal? I fill jugs with city water,then ph to 6.6 or so. I then notice that when I check water that has sat for several days,that the PH has risen again. Anyone else experience this?
 
Hey slim if you talking just tap water I’m pretty sure mine stays the same but I’d have to do a check on that. With nutrients i get a day or two before it starts to rise. That all depends on what’s being fed though too.
 
If I use white vinegar, ph will drop in the bucket back to what it was overnight. Currently using citrus crystals and ph remains constant when I check next day. Also when using chemical ph down from jug, stays the same as well.
 
Tap water generally has low ppm and low buffering capability (mine is 8.5ph and less than .1 EC, ph changes very easily).

Good point on the vinegar CBF, it is reactive and and it's generally the last choice for pH down. Recently using vinegar with ground egg shells to make a calcium supplement. Will post the ranked list of of agents when back on 'puter.

I think it really depends on the nute mix [MENTION=1485]Slim Pickens[/MENTION] and how much it contains buffering agents and residual reactivity.
 
This is tap water with no nutes. I filled a jug 2 days ago and it was 7.5. Checked the ph last night and it was the 7.6. I added 3 drops of PH Down,and it went to 6.7. The water division has been having a bit of a time getting Chlorine. I wonder if that has anything to do with it. Seems I remember reading some water facilities using chloramine which is a different animal.Maybe I should be reading the article again.

my memory....:dunno:
 
I routinely see this happen here in my area, BUT I do use RODI-water that is susceptible to these kind of fluctuations. It's one of the things I routinely see my water is drift that's been collected on earlier days. I added a 6 stage rodi filter because of summer time water issues. I want to get my water tested to see why it wants to kill my plants during the summer.:pissed:
 
I'm not sure of city water but I do know well water PH will rise if there is alot of rain . My well is typically 6.2 but went up to 8.4 in the month of July after 10 inches of rain . Its down to about 7.0 now
 
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If you place buckets of tap water out, chlorine will burn off, I imagine other additives would as well. That alone could make the PH fluctuate.

I fill 5 gallon buckets, and let um sit just to get the chlorine out.
 
I called GH about their PH Down,but the resident expert never called me back..(seems to be a re-currant theme these days). I checked a gallon jug that had been filled 3 days previous. The PH was 7.7.I then added 5 drops of PH Down and arrived at 6.7. Today it was again up to 7.7. I used less than 2 cups of that water and watered a plant to get some runoff to test,and it was 7.1.

chlorosis (2).JPG

I'm in Roots Organic soil,and I have a couple plants showing inter veinal chlorosis.I'm at a loss. (surprise surprise!) Wonder if I should add some Epsom or CalMag?
 
Yessir...480w led. I be addin in the Epsom pronto. If I could lug those 5gal water jugs,I'd go back to RO from the market. :(
 
I add the Calmag and give it a stir,then check PH and stir again, and then check the results if that is what you mean Pa.


I wonder if the PH down has become ineffective at holding the the level? Maybe I should be looking for a new brand?
 
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Slim Pickens said:
I am noticing that my PH'd water drifts higher when I don't use it promptly. Is this normal? I fill jugs with city water,then ph to 6.6 or so. I then notice that when I check water that has sat for several days,that the PH has risen again. Anyone else experience this?
Click to expand...

It has to do with the Hydrogen atoms in your water.

C02 in your atmosphere, air stones oxygenating your water. Chlorine evaporating although I'm not sure if that actually affects the pH.

...I'm way too stoned to get into it right now, but there's science behind it.

In ideal application, leave your water aerated 24 hours before you mix your nutes, and then adjust pH last. (Or mix, adjust and use, but know you'll be adjusting again the next time you go to use it.)

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edit:
Carbon Dioxide Absorption: When water is exposed to the air, it can absorb carbon dioxide (CO2) from the atmosphere. Carbon dioxide dissolves in water to form carbonic acid (H2CO3), which can lower the pH of the water. The reaction is as follows:
CO2 + H2O → H2CO3
The increase in carbonic acid can make the water more acidic, leading to a decrease in pH.

Carbon Dioxide Loss: If the water is exposed to air, it may lose dissolved carbon dioxide (CO2) to the atmosphere. This loss of CO2 can lead to a decrease in carbonic acid concentration in the water. Since carbonic acid is a weak acid, its decrease can result in a rise in pH. The reaction is reversed from the one mentioned earlier:
H2CO3 → CO2 + H2O
As carbonic acid breaks down, the pH of the water increases.
 
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Slim Pickens said:
I called GH about their PH Down,but the resident expert never called me back..(seems to be a re-currant theme these days). I checked a gallon jug that had been filled 3 days previous. The PH was 7.7.I then added 5 drops of PH Down and arrived at 6.7. Today it was again up to 7.7. I used less than 2 cups of that water and watered a plant to get some runoff to test,and it was 7.1.

View attachment 347328

I'm in Roots Organic soil,and I have a couple plants showing inter veinal chlorosis.I'm at a loss. (surprise surprise!) Wonder if I should add some Epsom or CalMag?
Click to expand...

Those look like fair sized plants. If they've been in that soil longer than a month and you have not added any amendments or teas yet, then yes, it may be a good idea to start looking into some. :)
 
I have read that chlorine will dissipate from sitting in the open. However, i've read that there are those other 'chlors' that do not. Chloramine, etc. Supposedly, they need some organic matter to expend themselves on. So, i will add a bit of organic matter to my little water res and let those baddies chew on that for a while (over night). Dunno how true it all is...but that's how i roll these days.
 
Honestly, the tiny amount of chlorine or chloramine in tap water doesn't hurt plants at all. It can inhibit some soil microbial life, if you are growing organically or biologically. However, city water is loaded with carbonates/bicarbonates, and often a random mix of cations like sodium, magnesium, iron, calcium that are often not in ideal ratios. The carbonates can build up in you media as they are not taken up by plants and can antagonize calcium and cause some pH challenges.

Also, when nutrient solutions interact with the root zone, plants take up a ton of NO3- and exchange it for OH-, which will cause your nutrient solution or substate solution to rise. NH4+ will nitrify and turn into NO3- when exposed to oxygen, thus releasing a H+ ion and causing your solution pH to go down. Also, K+ ions taken up by the plant are exchanged for H+ and will also cause your pH to drop. pH is very relative to cation/anion ratios that the plant needs, and their reactions to air, water, things in the water, things in the media, and root exudates.

So to answer your question, yes pH is constantly changing. But you also don't have to manage pH so tightly. pH swings in hydro, as long as they stay in the ideal 5.5-6.5 range, are actually beneficial and often times created by the root exudates trying to capture certain elements. I don't work so hard to keep my pH at a perfect 5.85 anymore. Just make sure your starting nutrient ratios are ideal for what your plants want.
 
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