Looks pretty stealth Brandon, nice :thumbsup:

Two things:
1) Are you checking the temperatures inside the cabinet? With 2 CFLs, no fan, and only one hole, I imagine it might be too hot for the plants and causing stress. Ventilation is definitely necessary for the plants. They take in CO2 and convert it to oxygen. If there isn't enough ventilation, it can stunt your plant growth. I guess by opening the cabinet door each day during the 12-on hours, this can help. But I'd still be concerned about temps.
2) Since you're starting from 12/12, is the cabinet lightproof? The hole in the back there seems like it might be a problem.

Good luck!