I have used multiple methods. One is kinda like the one above only i used a powerhead the end of a gravel vac and put the airstone in that and pointed it downwards. I have also used ceramic diffusers, vortex reactors, and inline canister filter reactors. On my large tanks i use the inlines only because they can be hidden under my tanks, and on my smal tank i used a ceramic diffuser. It's all a matter of preference as stated before. they all work it's mostly just aesthetic value.