CichlidFish.com - Fish That Think.

I currently have an airstone in each one of my tanks and i was wondering if what i was told is correct. I was told that having an airstone in a tank will promote good bacteria growth on the surface of the water, and these good bacteria will counteract the bad. My main question was how much is too much and too little for a tank, or is there such a thing?

bacteria growth on the surface of the tank? the "good bacteria" grows on substrate, decorations, media, etc. there are 2 sorts of the good bacteria, one gets rid of ammonia by turning it into nitrite. the other good bacteria turns that nitrite into nitrate.
http://www.algone.com/cycle.htm (picture)
it doesnt counteract any bacteria, but gets rid of the ammonia and nitrite, which are very dangerous to fish (nitrate is also dangerous, but only in large amounts).
an air stone helps aerate the water, and weakly circulates the water. its really bad if you dont have enuff oxygen in the water. and its bad to have so much bubbles that you cant see the fish or if they get so much bubbles up the gills.
what is the size of your tank again?

Well what you were told is 75% false 25% true... the thing about the surface is that is were the dead bacteria gather, sometimes you will notice a film or scum on the top.. that is them... the air stone helps aggitate teh surface to keep them from blocking off a majority of the suface and stoping your gas exchange. The air stone itself and the bubbles coming out of it really dont do much to aerate the water, as most of the gas exchange happens at the surface only... what it does do is displace water on it's way to the surface creating a slight updraft of water with it. Then the bubble hits the surface dispersing any scum that is around it. So the air stone does not in itself create oxygen rich water, you could have tons of air move thorough the tank butif you captured them all before they hit the surface you could still have fish suffering from oxygen deprivation... the bubbles must reach the surface to be effective. Hope that wasnt too confusing for you.


------------------
Save the animals, eat a PETA member!

Adam

Thanks for your replies, they were very informative. I have seen that film that you are talking about in other tanks before. I have a 10 gal tank and a 30 gal tank. In my 10 i think that it is a 5 inch air stone and the 30 i think has a 10 or so air stone. Are these the right size or does size matter on this situation ?

A good filter will help to stop the accumalation of dead bacteria on the surface.

It is good for aquariums to have a good circulation of surface water. The best way I have found to agitate the surface water, has been a good power jet.