Since you've increased your lighting, you also have to increase the number and
kind of plants you have. 80% of the tank should be planted, and at least at
the beginning, a lot of those plants should be fast-growing stem plants. They
will out-compete the algae for nutrients.

I would not reduce nitrate below 5 ppm. Your plants need it. Plant heavily,
plant fast-growers, give your plants all the nutrients they need (and yes, that
includes nitrate and even phosphate). A tank of plants that are growing well
won't have an algae problem.


Leigh

http://www.fortunecity.com/lavender/halloween/881/