06-05-2011, 01:04 PM
| || |
And it looks like diatoms. Commonly called brown algae. Very common in new tanks, usually during the first 1-3 months, then it will (should) be gone forever.
It is not actually harmful, except if it gets on live plant leaves it can suffocate the plant. Elsewhere it is simply unsightly. I would keep it off the front and side glass walls, it comes off easily with a sponge scraper.
Many "algae" eating fish will devour it, but I do not recommend adding fish solely to deal with algae. If you really like the fish as a fish, and it happens to have the benefit of eating some form of algae, fine. Fish add to the tank's bioload, and some quickly outgrow smaller tanks, and some can be downright nasty to other fish as they mature.