The best method to rid your tank of green algae blooms like you have, is first to limit the amount of nutrients in the tank. Go EXTREMELY light on feeding, I'd personally cut it out all together. Next limit lighting amounts, and make sure your tank is not in direct sunlight. You want to gradually get rid of the algae, and not kill it all at once. This will cause a ammonia spike, which is similar to NTS, but not the same. Another option you have is to get a LOT of live daphnia, and drop them in. They will start eating the algae, and your fish (if you have small ones) will eat the daphnia.