unless of course, your fish hops out of the tank...
good point. i got a fish once, and by mistake, instead of putting the open plasic bag in the tank, I put it on the living room floor. ( i can be a little forgetful) when i came back later, there was the fish, dead. lying on the floor surrounded by a little water and a Whole Lot of air.
I searched the web for days and finally came to understand the cause of death: Too Much Air!
so,I figure, as long as you have more air than water, you are probably ok.
The article cited by didy was discussing a
planted tank. a tank designed primarily to grow plants
I think that the writer of the article therefor assumes that the CO2 content of his water
will be higher than that of the air. in which case his statement could be seen as making some sense.only when it is taken out of context is it fully poppycock and nonsense.
Anyway, Not even didy's cited article suggests that "too much air" will hurt fish.
OP having a fish tank, not a 'planted tank' and not even having any live plants, the whole reference was rather :OT: .
so, IMO as long as you are not talking about an environment equivilant to my livingroom floor. (or the conditions RiVerfishgirl described) you don't need to worry a bit about "too much" air.