Do they do a good job? I would be putting it on a eheim 2213. I'm trying to get as much stuff out of the tank as possible. I'm not liking how the regular diffuser works. Seems as if the bubbles are not small enough and go straight to surface. Maybe mine is not working right? Ill see if I can find some youtube video of how others people work. Also do you think a inline diffuser with a inline heater will cut back out flow to much on a 2213? I'm not sure how much of a restriction the diffuser would be. But I heard the inline heaters do cut a little bit of flow.