Can Excessive Aeration Raise Ph?

[jnms]

I recently had to increase the aeration in my tank. Since doing so - the Ph has raised from 7.2 to 8.2 - The fish seem ok with it at the moment - though obviously I don't know what this may mean long term. It's been about 2 weeks since I increased aeration.

Any suggestions please? Do I need to be worrying about this?

 

[ellena]

What's the ammonia reading? It's alkaline so will raise pH.

 

[jnms]

Ammonia 0.0
Nitrite 0.0
Nitrate 35

 

[Liam50]

i honestly can't see how aeration would have increased the ph. have you tested again just to make sure?

 

[jnms]

i honestly can't see how aeration would have increased the ph. have you tested again just to make sure?

Aeration increases Ph because it reduces the amount of Carbon Dioxide within the water. If you add CO2 it causes the Ph to drop. If you add O2, then it removes CO2 which causes the Ph to increase.

I tested the water with an API kit and a Hagen kit just to make sure. They both give the same reading.

 

[Truck]

Do you inject CO2?

 

[jnms]

Do you inject CO2?

No CO2 injection.

 

[Truck]

Any new rocks or substrate, aeration has not caused the rapid PH change.

 

[jnms]

Aeration is the only thing that has changed. It has done this before when I added aeration. I can gaurantee that if I stop the air now, by tommorrow the Ph will be back to 7.2

Aeration – Increasing the oxygen concentration in your water will serve to drive down the carbon dioxide concentration. As discussed above, less carbon dioxide translates to a higher pH. Therefore, you can increase the aeration in the tank to raise the pH. To read about aerating your aquarium, reference the article entitled Properly Aerating your Aquarium in the article section of this website.

http/www.ratemyfishtank.com/articles/107

Not the best article - but if you do a search you will find plenty of information of using aeration to increase Ph.

 

[Truck]

the CO2 levels of a tank are around 6ppm and aeration will only drive up the PH if you are injecting it already.

What is your KH, what substrate are you using? what rocks do you have if any? What is the PH of your fresh tap water?

 

[jnms]

Tank

KH 14
GH 25

Tap Water

KH 14
GH 25

Doing a rough calculation - there is a difference of about 1ppm CO2 in the tank water. The tap water has 1.5ppm CO2 whilst the tank has about 0.2ppm CO2.

That doesn't seem enough of a change to account for the difference in Ph levels. So perhaps it is something else - however the raise in Ph only occurs when I turn the air stones on.

Is it possible that the air stones themselves are somehow breaking down and causing the Ph to raise? Alternatively, I do have a sand substrate which maybe reacting in some manner to the air-stones / aeration?

 

[drobbyb]

It's possible that they are made of a material that is raising your pH. I just can't see why they would make it out of something that isn't pH neutral.

 

[jnms]

I will try and get some different airstones.

That said, if there is only a difference of 1ppm of CO2 between 7.2ph and 8.2ph - they why wouldn't this Ph increase be due to the aeration?

 

[Truck]

I will try and get some different airstones.

That said, if there is only a difference of 1ppm of CO2 between 7.2ph and 8.2ph - they why wouldn't this Ph increase be due to the aeration?

how are you getting a 1PPM figure?