Does aerating a tank raise or lower pH?

[Devin R.]

I've tested my water and it reads somewhere between 7.8 & 7.9. I know that is to low for Xenia, they apparently like it around 8.1 to 8.4. So I was going to try adding a pipe without an air stone, because those make tiny bubbles and I don't want the bubbles to be to small, to the aquarium to see if it raises the pH. But I want to know how true raising the pH by aerating the tank is.
So is this true? or will I just end up with a lower pH?

[Aquarist007]

Originally Posted by Devin R.

I've tested my water and it reads somewhere between 7.8 & 7.9. I know that is to low for Xenia, they apparently like it around 8.1 to 8.4. So I was going to try adding a pipe without an air stone, because those make tiny bubbles and I don't want the bubbles to be to small, to the aquarium to see if it raises the pH. But I want to know how true raising the pH by aerating the tank is.
So is this true? or will I just end up with a lower pH?

very little oxygen will be absorbed via an airstone
better to crank up the skimmer and or increase surface flow...agitation

your on the right track realizing pH is a factor of carbon dioxide/ oxygen levels

xenia is affected by the levels of organics in the tank (Docs) more than pH

[redfishblewfish]

What could impact pH is carbon dioxide. In colder climates where combustible heating systems are used, this tends to be a problem during the winter months. If carbon dioxide is your problem, if you simply aerate your tank with room air, that is laden with CO2, it wouldn't cure the problem. The correct way to aerate you tank is to draw fresh air from outside. If you are running a skimmer, just run an airline to the skimmer from outside.

One additional note, you will want to make sure your alkalinity, calcium and magnesium levels are in line....the proper levels assist in maintaining proper pH.

Hope this helps.

[bertoni]

7.8 is fine for pH, and I would leave the tank alone. That's a fairly common level for a house with the windows shut. A number of Tanks of the Month run at that level.

Some tanks don't have enough aeration, and in that case, adding more flow or a skimmer will change the pH. The airstone might help, too, but they can make a mess. On the other hand, I said "change", not raise. In theory, the pH could drop during the day, if a lack of aeration is keeping more carbon dioxide out of the tank. Generally, though, I suspect that most tanks have plenty of aeration, and the issue is the indoor carbon dioxide level.

I'd probably check briefly for any sign of a surface buildup of oils or scum, and make sure the water surface was getting some good rippling going, and work from there.

[Reefvet]

Your tank can only absorb a significant amount of air in the top 1/2" of water. So movement of the surface and a skimmer are vastly superior to an airstone.

[tmz]

Oxygen has nothing to do with pH.
Skimmer's can raise oxygen levels and promote gas exchange for both oxygen and CO2. ERic Boneman in his series of articles demonstated that.
CO2 drives pH. If your room air is higher in CO2 than the tank more surface agitation will lower pH. If your room air has less CO2 than the tank ,surface agitation will help raise pH. Often just opening a window helps raise pH when room air has higher concentraitons of CO2 than the athmosperic level. Running an outside air line to the skimmer intake is another way to overcome high in house CO2 concentrations.