I have a 100 gallon tank with 4x55W CF's, onyx sand substrate, plants, 10 cardinals, 1 upside-down cat, 1 betta, 2 cories, 2 kuhlie loaches, and 2 pearl gouramis. Filtration: an Eheim 2028 and an Eheim 2216 on either side of the tank, 2 heaters. Filters disassembled and cleaned every 3 months (media rinsed but not changed). I feed the fish once a day, 50% water changes every other week. Don't want to use UV sterilizer since it destroys nutrients the live plants need to grow. Lights used to be on 12 hours a day but I've brought it down to 8 hours a day to see if it helps the algae problem, but it doesn't. The onyx sand and most of the plants are completely coated with slimy green algae, and I have algae that looks like long hair stringing off my plants. "Algae Destroyer" doesn't get rid of it, only blackouts for about a week at a time get rid of it. The real question is, how do I STAY rid of it?