Relax, this sounds about right for a fresh cycle of a tank. Your best bet is to increase water flow (add a couple of powerheads to prevent deadzones) increasing the water flow will also prevent cyano (red slime) from growing. While you are cycling try reducing the amount of time your main lights are on (I cut my light time from 8 to 4 for 2 weeks when I first start a tank). If you have a protein skimmer run it 24/7 if you don't have one I highly suggest getting one. By just doing those 3 things you can make it through the cycle phase without too much stress of a ugly tank but keep in mind you will have algae blooms but the key is to minimize the fuel in which algae needs to grow.
Yes you can siphon off the brown algae off the rocks, I have used a powerhead to blow it off the rocks and then a turkey blaster to get the out of the tank. Phosphates play a major role to growth of algae, you can run carbon and phosaban combo in a media filter to help reduce phosphates and polish the water.
Well then again this is IMHO, good luck...
BTW Welcome to WAMAS!!