Been trial and error DIYing today and built this small waterfall scrubber. So far the water seems well spread across the screen. I go the idea from here.
https://www.youtube.com/watch?v=QS24...ist=WL&index=6
I have used an A5 leaflet holder as it is the biggest I can accommodate in my Aqua Reef 300 sump.

I have ordered this light to power it.
http://www.ebay.co.uk/itm/2913996713...%3AMEBIDX%3AIT
I have also ordered some mirror plastic to attach to the back of the holder in the hope some light will be reflected back against the rear of the screen to get some algae growing there but not sure it will relect enough to be of use.
http://www.ebay.co.uk/itm/1216498197...%3AMEBIDX%3AIT