[CMG]

Ohhhhhh! Very interesting. Thank you.

So I not only need to hook up the airpump tube to the top of the bullseye on sponge filter but I also need to use an airstone? I think this is attached to the bottom side of the bullseye.

So what does an airstone do? Does it just diffuse the air coming out of the tube so that its not a just a strong flow but instead a spread of bubbles?

In my picture here the blue box is the air pump and the green is the tube for the pump that goes down inside the sponge filters tube (not pictured) and attaches to what the box says is a bullseye. and underneath the bullseye is another connection point that the airstone (pruple) would go on?