[SantaMonica]

Michael: You already have spores of algae in your tank right now as you read this, including green hair, green slime, and red/brown turf algae. But without enough light (and in the case of turf, flow and air), they will not grow. Algae grows first where it has the most light. That's the first part of how a screen works: It's just more light, out of the tank. The second part of a screen's operation is the turbulent flow across the screen; this brings many more nutrients in contact with the screen than just regular tank flow does. Lastly, if you are doing a vertical screen with a pump, and you put a wavemaker timer on the pump (on, off, on, off), then the "off" time will simulate the time between real waves in the ocean, which breaks up the "boundary layer" around the algae. This boundary layer slows down the passage of nutrients from the water to the algae. This last step (pulsing the water) is very important if you are going to want the true stiff red/brown turf algae, since real turf lives out-of-the-water (on rocks, pylons, etc).

Herring: Yes I was almost going to use 100W halides, but found a nice small 2-bulb 24" T5HO unit from Current. Most important was that it was thin, 1.5", since it will be on both sides of the acrylic. Looks like final measurements will be about 6" high, 6" deep, and 24" wide.