I was searching for a good DIY diffuser cause the airstone works but not that great, I came across a thread at another forum and gave it a try.... an unused cigarette filter! just unwrap it and peel apart till it fits in the airline, put about 1/2" into airline and leave 1/8 -1/4" sticking out...it works!!! The bubbles it releases are so timy that most of them are gone by the time they reach the surface!!!
Try it!!
Try it!!