Brown algae.

Hi all
I have slowly adding plants to my tanks.
I am constantly have to wipe brown algae
off of the plants. Why do I keep getting it?
Is it cause of the lighting? I just got new
lights. 1FS flouresant and a couple PG
incadesant bulbs.   Will I continue to have
this problem. This tank is an angel tank
with a few plants. Filtered w/ peat, untill
yesterday when I bought Blackwater extract.
I cleaned the plants 2 days ago. Now just
this morning brown algae covered them again.
I think this is due to the extract. Am I wrong?