So you want a 100 sq in screen. Lots of different ways to cut a screen to 100 sq in. So how do long narrow screens compare to short wide screens of the same area?
If you take lighting constraints out of the equation (meaning, you can adapt your light source to the screen vs the screen dims being driven by the lighting source) then a narrower, taller screen would tend to filter the volume of water that passes over it slightly better with each pass than a wider, shorter screen, because there is more contact time with the water from each pass. Conversely, the wider/shorter screen would filter less per pass. The flipside of this is that a wider screen moves more total volume of water across it. So it's really a wash. The reason why one might want to go with a wider screen is because they have a larger tank and they wish to turn a higher percentage of the water over the algae screen per unit of time.
I find a 6-7" wide screen works good for flow across the screen. In my builds shorts seems to spray out as growth gets toward the end of the cleaning cycle, wider seems to need a bigger pump or more flow then I still get spraying out of the screen to bar at the end of the cleaning cycle. If longer I think supplying the center of the bar would be better then the end as my builds are.
