My Pond Water's Green- How can plants help?

What can you do if your pond water's green and it really should be crystal clear? There are many reasons why a pond's ecosystem can be out of balance and water can turn green. Maybe one or several factors can be contributing to your problem. Let's start with plants. Alage, being a plant itself, will thrive in conditions where there is plenty of sunlight, lots of nutrients in the water and very little other plant life. Aquatic plants are an important part of a pond and will actually help control algae. The roots of the plants will absorb the nutrients in the water and if you have enough aquatic plants, will effectivley starve out the algae. How do you know if you have enough aquatic plants? Well, the pond industry generally recommends that at least 50% of your pond surface be covered with plants. That can be a lot of plants. Water hyacinth, parrots feather, creeping buttercup, forget-me-nots are a few "spreading" type plants that can help provide coverage. Plant bogs are very effective in keeping the water clear because the pond water is forced through the peagravel areas and the roots of the plants. Further discussion of plant bogs or types of plants that work well for controlling algae would be helpful. Please post any comments that will help out your fellow pond hobbyists.