Co2 From Air Using Airstones

[ShinySideUp]

If a co2 system is used to provide the gas to plants then canisters of 100% co2 are used. Let's say that the co2 system uses 1 drop per second which is turned into, say, 50 bubbles (I've never seen one so I'm, guessing). Now that is 50 bubbles of neat co2. But what if I use an air stone driven from an air pump, I now introduce 1000's of bubbles per second from a source that has 3% co2 i.e. ordinary air. I only have to have 30 times the number of bubbles as a co2 system and I'm putting the same amount of co2 into the tank but at practically no cost.

Why could I not use an air stone and pump to introduce co2 to my tank?

 

[Mikaila31]

Cuz airstones hardly dissolve gas into water. Also the CO2 will not dissolve from the air any more then what is at equilibrium. Things diffuse from high concentrations to lower concentrations. CO2 gas dissolves into water when you inject it because the water has a lower concentration, it also diffuses out of the water into the air because the air has a lower concentration. When you inject air you are injecting the same concentration that is in the water. You can inject all the air bubbles you want and its not going to rise about the concentration that is in the air.

 

[ShinySideUp]

Cuz airstones hardly dissolve gas into water. Also the CO2 will not dissolve from the air any more then what is at equilibrium. Things diffuse from high concentrations to lower concentrations. CO2 gas dissolves into water when you inject it because the water has a lower concentration, it also diffuses out of the water into the air because the air has a lower concentration. When you inject air you are injecting the same concentration that is in the water. You can inject all the air bubbles you want and its not going to rise about the concentration that is in the air.

That makes sense. Thanks for that.

 

[zain611]

What i heard in a video from an tropical aquarist is that nitrates stick to the bubbles and when it pops up the water it takes it out and what i read up in a book is that nitrite can rise from lak of oxygen so i would say an air pump lowers it but 4 weeks ago when i restarted my tank cycling by changing my sponge i had no nitrite reading since then and i have a air pump