I'm thinking that you'll find it pretty much impossible to get rid of algae with that much light. Scale back to about 3 or 4 wpg and I'm sure you'll see a big difference. Hours per day doesn't matter nearly as much as actual wattage when it comes to algae reduction. Fewer hours per day means less algae will grow that day, but the balance is still off so you'll just have the same problems, moving slower. Plants won't grow as much, algae won't grow as much. Reducing wattage will tip the balance more in favor of the plants and you'll see algae dying off, whereas plants continue to grow.