[SantaMonica]

Power of turf: This is the main reason I wanted to get some turf going. It appears to be not a little, but a GIGANTIC leap in N and P processing, for a given size. The graphs that someone posted in older posts (I think taken from Dynamic Aquaria) seemed to show turf being 20 or 30 times higher in processing power per unit size. Nobody mentioned it, but I surmized the reason was the high CO2 content of the air.

Raceways: I thought about a raceway (as in the linked pics, or one like Paul B. has), but it seemed to me to lack the air-portion of a surge. I'm sure raceways work, but maybe you need a larger size for a give amount of processing. Also, since they are horizontal by design (and although they fit perfectly with a 4-foot pc bulb), they kinda eliminate any chance of placement below the tank.

Growing in tank: Good to hear of another case of turf keeping to it's own area, and not getting into the tank.

"Vertical Bioreactor": Now that is a cool name! From the pic it looks like he has water running down those sheets of algea.

Growing on box: This just occured to me... How would the turf grow on the inside of the box, when the inside of the box is dry? Remember it's vertical. The horizontal ones, of course, were basically tanks themselves filled with water. But with this waterfall version, the water should stay on the screen and flow down. This is assuming that you don't fill the box with water, of course; it would need to drain as fast as it comes in. In this case the box is not a tank at all, but just a platform to hold the lights a few inches from the screen. You could even cut out the sides of the box to get more air in.

No-spraybar: This is the idea of just filling and emptying the box, which would indeed give a wet a dry phase to the screen, but also gives us the just-mentioned algea on the walls of the box. I see a further possible drawback too. I read a few times of a possible boundary layer around the algea, where a strong surge helped break through (thus getting more CO2 to the algea.) If true, then the weaker the surge, the less processing you get. With the spraybar, while it's not nearly a "surge", it's still stronger than a "slow fill" of the box. I do realize that raceways work with no surge at all, so somewhere among these tradeoffs, I'll have to decide what give the best processing, the smallest size (really important), the lowest maintenance, and the easiest build. I must say that a simple "fill the box" method is about as easy to build as it gets; it could be tested with a 5 gal bucket with the screen in it, and a light shining down on it. As for a spraybar causing deadzones on the screen, that seems to be just a design problem. With enough flow, or possibly two spraybars (one on each side), and properly drilled holes or slits in the tube, wouldn't it be possible to saturate the screen every time?

Joe: I do like reading but I have a bit too many projects going now to add another. Since this is a hobby I like to be able to just test stuff, as long as it won't kill anything. But why don't you stop over when you are over here... the tank is in my office. By the way I'm considering a seagrass tank with seahorses to be the fuge for the reef.