I would recommend Right Now! bacteria for a 24 hr cycle. I am a user and it works!
See last photo here for detailed water testing using this bacteria in my 300g SW system.
http://bwclark.smugmug.com/Aquariums
See last photo here for detailed water testing using this bacteria in my 300g SW system.
http://bwclark.smugmug.com/Aquariums