Are you trying to grow out these frags to add them to an established tank? Because under that lighting you will find slow growth rates and no coloration other than brown. If you are just looking at keeping SPS corals alive and not necessarily growing them quickly, then yes it can be done. I have a staghorn monti in my nanocube under PC lighting and it has almost grown to cover the entire circumference of the tank. However, it is totally brown, no coloration whatsoever. I have also kept a pocillopora and monti cap in there in the past, before moving them to my main tank with halides. I have 69 watts of lighting in the nano, and the monti is only a couple inches below the waterline. So if you are to attempt this I would recommend packing as many watts of PC bulbs as you can in there, with the majority of it being 10,000K. Stick with some of the less demanding SPS corals, and don't expect to see pretty colors or amazing growth rates. Because of this, I would recommend you turning it into a nice little nano reef rather than a plain frag tank with some eggcrate and brown frags. Get a nice rock structure in there with some softies on the bottom and the SPS up on top of the rocks and you'll have a nice little environment. This would be my best suggestion given your situation. Good luck!
