I hope it helps. :smile:
If neither of these things helps clear it up, try getting your water tested at another LFS. After fighting a PH issue for several weeks I went to one of my LFS and had them test my water, and they told me my water was fine.
I was relieved, but things still weren't looking right in my tank. About a week later I took another water sample to another LFS that I trusted a bit more, and they tested it and sure enough my calcium, and ph were way off. They explained what I needed to do to get it back to normal, and how long it should take. The first store was one that I normally trust for advice, but as it turns out the person doing the testing was kinda new, and didn't really know what he was doing.
I had a cyano aglae outbreak at one point, it wasn't terrible, but it was in a tank that I couldn't really add too much flow too, so I tried a product called chemi-clean. It's a very small white bottle, about half full of a powder. I followed the directions exactly. You add so many little spoonfuls per gallon. Overnight the cyano was gone. Amazing stuff. It didn't affect my corals, my octopus, (notoriously sensitive to chemicals), my other inverts, or my fish. It's mainly for use against cyano, which may or may not be the brown algae you were seeing. I'd recommend trying to add flow to the tank, and reduce your photoperiod first, but if those don't work in a week or so, I'd give this stuff a try.
