Disolved O2

Is there a prefered way to get more oxegen in the water ? Alot of ways I've thought about seem to be nitrate builders . The last 3 years I've just run airline to the output of one of my powerheads , but don't like the tiny bubbles in my tank . I don't have a protine skimmer , whitch I'm sure would help , but with all the DIY plans out there I haven't built one yet . I wont buy one as I think the prices are out of hand for what they are made of . Any suggestions ?

Bren

So I really don't need air stones or a way to introduce the air directely into the water, just surface disruption ? If that's truely the case I will be building a spray bar to hook into my Fluval 304 return. I have a tendacy to look at things mechanicaly, if I'm not puting air to the water how is it getting there. I do understand gas exchange, I can see that happening at the surface but not farther down. I guess if it happens in the gazillion gallon aquariums we call oceans it's gotta work at home in my 55g.

thanks
Bren