I have a 3, as well. I run NO flo, only and I keep great(but limited) coral. I also get a fair bit of afternoon sun. I put a third NO tube on the second flap. I believe that you can not do VHO, because of the heat. (I have VHO in my 55 gallon reef, and I keep two 4 inch fans running to keep it cool.) I can not figure out where I would put a fan in that system.
However, I have also explored the PC option and it will work. (As I have posted before, sorry to repeat myself). When I get around to it, I am going to replace the two tube system which came with the system for a retro fit PC, from an online company and keep my third NO tube as my "blue" light.
Good luck,
Connie
PS: I keep LPS (frogspawn and hammerhead) star polys, green and purple mushrooms, buttom polyps.