There were a few people that showed a little bit of interest in this, so I figured I'd post about my setup, along with a few pics. It consists of a piece of PVC with a 1/4" slit cut into the middle of it with 2 sheets of plastic canvas (the finer grid) zip-tied together. It is approximately 9" x 11" of usable/colonized surface area, which adds to 198 in^2 double-sided. I think the usual recommendation for my tank size is 100 in^2, to put that into perspective. I spent a couple of hours over the course of a few days roughing the screen up to make it suitable for algal growth, which I accomplished using a hole saw bit and some elbow grease. I use 2 40w 2700K spiral compact fluorescents to provide the light and I push approx. 700 gph of water through the scrubber (from the return, which is an old mag 12 I used on my previous 75g tank). It gets cleaned weekly, which takes about 5 minutes. This is all on the 40g breeder in my sig, which is about 50g of actual volume. I still use a protein skimmer and carbon, but I don't need to use GFO or any sort of other nitrate reduction because of the scrubber. I am also able to feed much, much more heavily than I used to or that most people would feel comfortable with. I don't have that much along the lines of coral at the moment (or fish, for that matter), so most of the food that goes in is actually to keep the scrubber growing properly. I noticed that if I back off on food addition, my nitrate will rise, while phosphate remains at about .03 ppm. After picking up the feeding, nitrate drops and phosphate stays about the same. In any case, it has cut down on my costs for GFO, which was beginning to get prohibitive and a little tedious. Plus I like the fact that I'm not adding anything else chemically, since the algae tend to remove more than things than they contribute. In all, this iteration has been running for about 3 months. It does not cause algal growth in the display and it does not yellow the water, because you clean it outside of the display and rinse it prior to placing it back--this is contrary to what many will say and contrary to what I used to believe. In all, it is an effective, relatively unique way of accomplishing the same end result. Now for some pics:
About a week after setup:
Taken today, about 3 days before I'll clean it again:
The lights are really yellow, so it can be a bit deceiving about the amount of growth. I'll take some more pics prior to cleaning it while it is in sunlight, which should give you a better idea.
