I have been tinkering around with the idea of a frag system ever since I started the fish room. At first I thought I wanted a large scale frag system, but have found that this stuff takes a little more time to grow than I was expecting

. Operating costs and maintenance time are also factors that have helped me come to the decision of building a small scale, inline system that will complement the main system. So here is what I have come up with....
Here is a picture of the space I have to work with:

I would like to use a 20L tank. 30x12x12. I was thinking that I could direct the end overflow that you can see in the picture above to the tank that would be sitting on the wire shelving. Just cut the pipe down and put a coupler on it and plumb it over in 1" to the tank. Stick a gate valve somewhere to control the flow a bit and either build some little maniflold or just have it empty in. Then build a glass overflow exactly the same as the one in the main tank. Just have 1 1" bulkhead in the overflow and run the plumbing back into the sump. I'm not sure how big to build the overflow box. I punched in some numbers on RC on their drain overflow size calculator. I punched in 600 for the gph which I belive is the volume for a 1" bulkhead and it says I need 9 linear inches of overflow. Can anyone back this up is this the right train of thought? I would like to get away with drilling just one hole.
For a light I thought I would try 96W T5HO. I really dont have any experience with T5's. I would like to used them just to try something different than what I have. Possibly cheaper to run than MH right? How will the growth and coloration be with these? What combination of bulbs would I use?
I would love as much creative feedback as you guys can offer up? What doesn't look right about this? What am I not taking into consideration in your eyes? The only thing I'm quite sure about is that I would like to keep the system relatively small. Would be willing to go a bit bigger if necessary. For frags I will be doing Zoas, Some LPS and Ricordea and Mushrooms and a few other softies.
I'm really excited to see what you guys have to say about this!
Another shot of the space. Would be on the shelf where the 2 part stuff is.
