Is Brown growth, like algae but brown "thread algae". It's on a few larger rocks and on the far glass. Should I scrape it off or get an otto/algea eater of some sort. 3 Otto's died buy pump in a 6-8 month period, the last being fairly recent. Then the brown stuff came. Snails? , what's best, it's unsitely. I have Tiger Barbs and some others in a 50G. (4feet long). 8)