You could cut it back a bit, but I don't think the light is your problem. I think every new tank goes through the brown-slimy-algae stage. Just try to scrap it off the glass and suck it up a bit when you do water changes, and it will probably take care of itself.
The other possibility is your water. Are you using properly filtered water? If not, you might be introducing phosphates into your tank that could promote algae growth. Switch to ro/di water if you haven't already.
If you cut your lights, give it time, and use ro/di water, but you still have algae problems, then you might plant some macroalgae to pull nutrients out of the water, either in a refugium (maybe chaeto) or in tank (something pretty, like some kind of caulerpa). You could also add some algae eating animals, like snails.