Empty the Skimmer weekly to ensure a good water flow through the system.
A Pool Vacuum should be used weekly to remove non floating debris accumulated on the bottom. Some water clarifiers will form solids which drop to the bottom and can then be vacuumed up. Submerse the vacuum hose, filling it with water and excluding air before connecting it to the attachment in the skimmer.
Regular Brushing will ensure that algae will not build up on the sides and the bottom of your pool and pay special attention to areas around steps, lights etc where water movement is minimal.
Clean off dirt from the water line if it appears as this could be a breeding ground for algae, using a chlorine based cleaner.