When I first set up my 128 g aquarium, it developed a vicious green water problem that lasted for weeks. I tried doing water changes, adjusting water chemistry, etc. with no success. Finally, I was told by a pet shop owner to just buy a cheap diatom filter. I ran the diatom filter for one week and that took care of the problem - no further problems with green water. I was told that by removing the phytoplankton, that then allowed the regular algae to get established and use up the nutrients (along with the plants) that had caused the phytoplankton bloom to start with. No further problems with algae for a number of years - until this nasty outbreak of hair algae. I realized that I replaced the old metal halide bulbs early this summer. Perhaps the increased strength of light along with the brine shrimp while discontinuing the use of Excel was the cause. I think I'm going to try dosing with Excel for awhile, do lots of water changes and consider the possibility of adding CO2.
