Often the brown "algae" is actually diatoms that form in new tanks, or when water changes and maintenance have been ignored. Up your maintenance and it will go away.
I Just got home from working in Alaska I haven't had this problem in a year or so. . I'm back on more regular water changes. I usually do 20 percent a week- This tank is a 55 community. The water is Always sparkling clear though and my fish are very healthy in there.
My wife and I have 8 tanks and counting. This summer I'm setting up the GARAGE!!!
clear water doesn't always mean good water i would bump your water changes up to 40% a week especially if its a community tank and you have a lot of fish.
