Having a battle with Green Thread Algae- Removed all the plants and pulled all the algae off. Tossed what was completely covered. Kept plants submersed with no light for 5-6 weeks. Replanted in a tank and kept lighting down 3 hours a day for a week and then slowly and gradually brought it back up to 9 hours a day over a months time. Thought I had it beat. It's back. Not that bad at first but it's getting more and more. Any advise?