Does ur meter do this?

Hello friends, not sure if this is the place for this ? so if it needs to b moved please do so... So, i use a hanna grow n check combo continuous meter (sepperate probes) and i have noticed that when i have the airstones bubbling in the rez. or even when i give it a good stir the ph reading will go down .2 - .4 then when i unplug the pump and the water settles the ph will raise back up that .2 - .4. I know this is not a lot but it is enough that it makes it hard to know if im in that sweet spot and b4 i noticed this i had a couple issues from ph problems, so now i take my readings in still water but it is hard to b sure what im really at once the airpump is running. I do keep both probes clean and calibrated and they r never off by more than a tiny bit at ph 4 or 7. I always keep both in ro water for storage and have been using the set for less than a year. So im wondering if anyone has noticed this with their set up or if someone can maybe try and c if it makes any difference? Thanx for the help

Anyone? Could really use some feedback...

This is a super complicated question that can't be explained without going into chemistry but I'll try to keep it short. lol





So depending on your water and any buffers you are using or are found in your nutrient mix, the pH will either go up... or down when you agitate or pump air into the reservoir.

taowolf said:

this is a super complicated question that can't be explained without going into chemistry but i'll try to keep it short. Lol

carbon dioxide dissolves in water to form carbonic acid (h2co3).
Co2 + h2o -> h2co3.

Carbonic acid reacts in water to form hydronium cations (h3o+) and bicarbonate ions (hco3-).
H2co3 + h2o -> hco3- + h3o+.

The general result is that the ph of the water drops away being neutral towards being more acidic when the water is exposed to the atmosphere. Agitation/stirring/bubbling will alter the level of carbon dioxide dissolving in the water.

But it doesn't end there. Alkalinity (the ability of the water to buffer acidity) comes into play as a wildcard as to how altering the amount of carbon dioxide in exposure to the water will impact ph:
​

View attachment 1237015

so depending on your water and any buffers you are using or are found in your nutrient mix, the ph will either go up... Or down when you agitate or pump air into the reservoir.

Click to expand...

dude you know your stuff al give ya that

i appreciate the info, really, but what would u suggest? just unplug the pump for 30 minutes when i take my readings? does anyone else notice this difference?

I just read someone having a similar problem. The fix was to take a sample (just a few ounces) out of the res and test it.

thanx for the response, will do

i had the same problem, also noticed if it was too close to cfl lights it would give me wacky readings. I just unplugged the pump and got a stable reading.

TaoWolf definitely knows his shit, I back him up 100% (not that he'd need it).

My reservoir rises when I run an air stone.

TaoWolf said:

This is a super complicated question that can't be explained without going into chemistry but I'll try to keep it short. lol

Carbon dioxide dissolves in water to form carbonic acid (H2CO3).
CO2 + H2O -> H2CO3.

Carbonic acid reacts in water to form hydronium cations (H3O+) and bicarbonate ions (HCO3-).
H2CO3 + H2O -> HCO3- + H3O+.

The general result is that the pH of the water drops away being neutral towards being more acidic when the water is exposed to the atmosphere. Agitation/stirring/bubbling will alter the level of carbon dioxide dissolving in the water.

But it doesn't end there. Alkalinity (the ability of the water to buffer acidity) comes into play as a wildcard as to how altering the amount of carbon dioxide in exposure to the water will impact pH:
​

View attachment 1237015

So depending on your water and any buffers you are using or are found in your nutrient mix, the pH will either go up... or down when you agitate or pump air into the reservoir.

Click to expand...

+rep smart guy