I have a planted 10g tank lit with 30 watts/12 hours a day. I'm using diy co2, and a power filter with peat and foam inserts. Water ph varies between 6.6 and 6.8. Some fuzzy black algae was brought into the tank by a plant that i did not check carefully enough, and now it is beginning to spread to other plants. How should I handle this outbreak? Thanks for your ideas!