Lowlight corals ...

Assuming that you have some sort of basic flourescent fixture and can replace the bulb(s) with standard (Normal Output) bulbs appropriate for a reef tank, most mushrooms and polyps will do well and offer a lot of variety in terms of colors. Chili corals also need minimal light. Some leathers are also pretty tough and can get by with less light, but you would want to place them near the top of the tank. Good luck and enjoy!

Mushrooms would work in low light, like a double normal-output fluorescent fixture. I wouldn't put a leather under anything less than 3 watts per gallon, and even then I would have it at the top of the tank.