I have a 175 gal bow front tank and I am contemplating copying the SM100 design but increasing the height to get double the screen area. I only have room for one SM100, but I have plenty of vertical room above my DT. This way, the flow characteristics can stay the same and I won't have to deal with 2 SM100's. I can divert the return flow to feed the ATS and save on adding a pump. I will probably keep some of the return jets bypassing the ATS and valve them for controlling the amount of flow into the ATS.
I am considering using the CurrentUSA Nova Extreme 1120 light fixture with 4 T5HO tubes, but I am concerned whether the spacing of the T5 tubes are too close together. From what I gathered, the T5 tubes are spaced at 1.5" centers. So, in the existing SM100 using the 1124 with 2 tubes, there is 3" height of light shining on 5" of screen. For the this design using the 4 tube 1120, there will be 6" of light shining on 10" of screen. In the first case, the reduced light region is 1" on each side whereas in the second case, it is 2" on each side. I am guessing also that the center region of the screen will get more light form the 4 tubes than 2 tubes since the distance from the tubes to the screen stays the same.
Is this something I need to be concerned about? Santa Monica, do you have any plans to offer a model like this?