Air in water

[uberdave]

Question, if you have a sump with an air stone pumping air , is it the same as having the air stone in the main tank?

[ZX10R]

Yes I have two airstones in my sump.

[Dkarc@Aol.com]

So long as the water pump is turning the water over in the tank, it is essentially the same. Only main difference is the air diffusers in the sump are probably in shallower water, which will reduce the gas tranfer efficiency when compared to the deeper water in the main tank. Shorter retention time means less efficient transfer of gases (oxygen, nitrogen, CO2, etc). In a typical aquarium, this usually doesnt mean a whole lot as the BOD isnt terribly high (though it can be if the system is not maintained). But if we were discussing a commercial operation, it would be a different story.

Also, if your water pump were to die on you, there would be no air getting into the tank. I always prefer to have air in the main display tank for this reason. I tend to keep some in the sump as well (to help prevent detritus from settling).

[Willie]

One of my good friends is a Director for ACA and keeper of all things African. So we seldom see eye to eye on anything in the hobby.

The one thing he and I agree on is that large fish do better with is vigorous agitation. We both use powerheads to inject air in any tank 75 gal or larger.

All hobbyist books say that air bubbles are not particularly efficient in oxygen transfer, which mainly occurs at the surface. In both our experience, the fish do way better with lots of air bubbles. They are more lively, eat more and swim more.

Just my 2 cents, Willie

[Jhhnn]

One of my good friends is a Director for ACA and keeper of all things African. So we seldom see eye to eye on anything in the hobby.

The one thing he and I agree on is that large fish do better with is vigorous agitation. We both use powerheads to inject air in any tank 75 gal or larger.

All hobbyist books say that air bubbles are not particularly efficient in oxygen transfer, which mainly occurs at the surface. In both our experience, the fish do way better with lots of air bubbles. They are more lively, eat more and swim more.

Just my 2 cents, Willie

Bubbles breaking at the surface greatly increase gas exchange by breaking surface tension, so what you're saying makes sense...

Obviously, there's a point of diminished returns where more bubbles won't provide anything more than marginal improvement...