I have been running the 9001 on a 22L AquaMaxx bookshelf-type tank. I had to move the magnets to an adjacent side to fit it in a tiny overflow box. It is QUIET. The tank has no cover and it's in a classroom, so quiet plus tiny is why I chose the Tunze. Mine makes tea-like bubbly skimmate just like yours - I have very little bioload. Tank is supposed to be for frags and now all it has is live sand and rock, urchin, couple snails, couple frags and some hair algae where the urchin cannot reach. I am loving the Tunze 9001 so far.
Your tank is looking healthy. That shelf kind of rock you attached on the right is great! I wonder if any corals can grow up that tall vertical branch. Close call with your fish - yikes.
Could you explain your ac30 fuge? Don't know what an ac30 is.