Thanks for the interesting feedback. My stock skimmer, although noisy, each week does remove quite a lot of thick slim (I run quite dry). This has convinced me not to switch it off, as my view is all that dirt is better out than in
This dirt is with only two small common clown fish fed once a week and a number of corals on a bare bottom, so the bio load I believe is quite low.
I've looked at the Tunze 9004 and I have seen it does fit in another thread, but really it looks too tight for my liking. Also, when the cup overflows, and one day it will, I'd be worried about water running over the rear of the tank and not back into it! Flood worry!
So not sure what to do, perhaps just got the live with the noise :-(