I have an Aquascapes water feature that has an algae problem. It is just green water and build up on rocks. There is no floating algae. Which algaecide should I use to control this green water and have clearer water?

There are two kinds of algae; green water and string algae. Your pond needs balance and the way to get your ecosystem balanced is the use of beneficial bacteria on a regular treatment program during growing season and the use of plants, rocks and filtration in your pond.