I'm not sure about after market direct fits on that model, someone here will know I'll bet. In the mean time, can you attach some clear tubing with an angular cut to redirect the flow in an upward fashion, for a little better surface turbulence? You can also take clean paper towels and lay over the surface and remove to get some of the surface proteins off the top, but that seems temporary since they are just being produced and sent right back into the system at a consistent rate. I never can see my surface scum until I let the water levels drop, how about just keeping the water level up and not addressing that scum layer? I know what they all say about Oxygen permeation, but that's never really been an issue with some of the dirtier nanos I've had because they really aren't that dirty, speaking from a captive reef perspective. I'd be more worried about systemic nitrogen and organic compounds in suspension, but as long as your bioload is reasonable I say just take that scum as part of a non-skimmed nano system. Breaking it up makes me feel more confortable in the mind, from an aesthetics point-of-view, but if it's not exported or fixed in some way I say don't bother to mess with it if it's not wrecking your system in terms of nutrient fertilization.
