When I finished my cycle I had a forest growing so I turned my lights out for three days and on the fourth slowly started turning them back on a few hours a day till eventually I got to the 9hrs a day now. I will slow its growth allowing any crabs or snails to get ahead of its growth. You have fish correct? Is your tank in a well lit room? You should be able to get away with it. Next thing is figuring out why you have so much in the first place. You have an aggressive tank correct? Probaly messy eaters. Either lessen what you feed or do more water changes its the only way to control the nutrients that feed it. Hope that this helps a bit.