Really the only way to stop algae dead is to grow lots of plants. If your brackish water aquarium has an SG of 1.005 or less, this is the best option. A tank with vigorous plant growth will have little or no algae. An SG of 1.005 is going to be fine for figure-8 puffers, gobies, glassfish, mollies, and all sorts of low salinity brackish water fish.
For tanks with a higher SG, as necessary for things like monos and scats, then plants are less of an option. I'd agree with AMS's comment about sand and algae magnets. In sandy aquaria, you need to take care cleaning the glass. Personally, I prefer a soft nylon pad for cleaning glass. For the ornaments and rocks in a brackish tank, I don't see any mileage in keeping them clean at all. The best tanks look "lived in", and for me, that means the rocks are dark and covered in algae, not shiny white lumps.
Cheers,
Neale