Jaden wrote in :

Joseph Arseneau wrote:
Hi guys,

I have an established 2.5 gallon tank, that currently has 10 fish in
it, no bigger than 2 inches each. I am wondering what I can do to
control my algae problem. I currently have an 18 watt light on top of
it with no live plants. Any help would be appreciated.


Are these figures correct? Your tank is MASSIVELY overstocked. I always
use the rule of thumb of 1 Inch per gallon of fish - keeps you out of
trouble.

You have 20 inches of fish in 2.5 gallons.....

....and you've got too much light. In a fish only freshwater tank, 1-2
watts of lighting per gallon is more than enough. Get some floating
water sprite, to knock down the lighting, or get rid of your current
light, and use ambient room light for observation.
What you've set up right now is an algae factory (lots of light, _LOTS_
of fish waste). About the only other thing you can do to help the matter
would be 80% water chanes every other day, until you can get a 20 gallon
tank, that is.

DaveZ