night lighting?

anyone use any night lights as I remember someone telling me there are very
few dark nights on a reef. it's just my algae seems OK when the lights are
on but first thing in the morning the brown scum is back on the rocks and
gravel. I have 8 red legged hermits but no turbo snails, should I buy a few
for my 36 gallon tank. what about water movement, may more powerful
circulation pumps help out. this has all started from upgrading my MH.

Robin

36" x 18" x 15" with 36 x 15 x 12 sump with a Rio1700 return pump and prizm
skimmer in the sump and 2 x 402 Hagens at either end pumping forward and 2 x
301 in the middle connected to a wavemaker. I'm doing 9 gallon water
changes every other day but its persistent.