I Need Scrubber Help

[k7iou]

I am trying a experiment with my 12 Gal Nano Cube. I started getting green hair algae on the live rock so I built this to try. Screen size is 5 3/4" X 4 3/4". I roughed up the screen good, water flow is good, soft white CFL 9 wts actual 40 wt equivalent. I originally had a bright white higher wt bulb which was way to bright, 100 wt equivalent. Its been running about 5 days. I tried rubbing green hair algae into screen and yesturday I put a small piece of live rock that had algae growing on it in the scrubber under the screen. This morning the algae disapeared on the piece of live rock.
Am I doing something wrong? I am wondering how long before the algae starts growing on the screen? My nitrates @ 0ppm and phosphates 0.5 ppm. CA 420, dKh 8
I also have foil lined the scrubber box outside on the front and back. 18 hours with timer. For simplicity I put the light on top, I can change it to the back if need be.
Any input would be greatly appreciated.
I want to see if the scrubber works for me without modifying the Nano as it has a one piece top, then upgrade to a 55-60 gal tank.
Thanks

[SantaMonica]

The light needs to be on the side, not the top. Clip it on the side, and at least you will have once side growing in a week or so. Don't put a rock, or pieces of algae, on the screen. Just let it grow.

[k7iou]

Thanks for the reply, I actually did that this morning. :)
Does everything else seem correct?

[SantaMonica]

Well screen roughness matter, which I can't see from the pics. Flow too.