Brown/Rust colored algae

Question
I have a 10 gallon tank that has been set up for about 3-4 years.  I have 5 small fish (species?).  I'm not sure of the PH levels.  When I got my tank the light attached to the top had broke and I never bothered to replace it until now.  Two or three weeks after using my new light algae like a brown/rust color started to appear.  I don't know if it had anything to do with the light or not but now all my gravel which is glass shaped rock is just covered in it along with everything else.  I did my weekly water change yesterday and actually took out the gravel and cleaned it.  really yukky :(  First question:  Why after all this time would this algae appear?  Second question:  Could this be from the new light or a combo of factors?  Please help my fish bowl is turning into a swamp!!

Answer
Hi Tracy;

Brown algae grows in tanks with too low an intensity of light. It can't grow in the dark so now that there is a little bit of light, brown is the one you will often get. Green algae needs lots of higher intensity light.

You might want to switch to a brighter intensity light bulb. If yours are the incandescent type, see if yours will hold the compact fluorescents that screw in the same type of socket. They put out great light and in my tanks they grow plants and green algae like crazy.

Here's a page about algae, just scroll down to the part about brown algae;

http://www.fishpondinfo.com/algae.htm#type

At Your Service;
Chris Robbins