blue-green algae (Causes and Cures)

> From: Jayme Donnelly <Jayme_Donnelly%BOND__NOTES at notes_worldcom.com>
> I wouldn't become overly alarmed and "freak," but then again, I would
> take this seriously.  The appearance of Blue-Green Algae means that
> something is wrong in your conditions in either the water quality
> (conditions) or lighting.
> The two major causes of Blue-Green Algae is poor water quality
> (nutrient rich water), or dim (low) lighting.

I'll have to take exception to these statements.  BG algae is not
necessarily an indicator of bad water quality nor low light.  We 
typically see small patches around the filter inlets right under the 
lights.  Our nitrates are usually <20 ppm.  Our discus tank as a bit
right now and it's nitrates are <5 ppm.  

We typically see it in our tanks near areas of high water flow and
bright light.  BG algae can fix atmospheric nitrogen and doesn't need
a source in the water. 

Generally, BG large can indicate:

. good water quality 
. bad water quality
. low light
. high light 

> Use the "only put in what they consume in 5 minutes" rule.

Unless you have Rainbowfish. of course.  They can eat quite a bit in
20 seconds.