Too much organic material in your pond or water garden puts algae into overdrive by providing nutrients that cause it to grow. Besides obscuring the beauty of your vividly colored fish, algae rob oxygen from the water and emit noxious contaminants that can kill them.

Ultraviolet (UV) clarifiers work by employing that part of the light spectrum to rid algae of its ability to reproduce. Once destroyed, the microscopically tiny algae form into larger clusters that are easily eliminated by common filtration systems.

Sun-blocking plants and those that provide abundant supplies of oxygen present another easy answer to maintaining a clear water environment for your pond. Floaters like water lilies, lotus, water hawthorn, four-leaf water clover, and yellow floating heart reduce sunlight by substantially shading the water surface and thereby impeding algal growth.

Water hyacinths have become a recent rage, especially for the lazy among us. No soil is required for these beauties. Toss them in the water and theyre planted. A water hyacinth isn't just another pretty face, though; these plants do their part in the war against algae and blanket weeds by keeping sunlight scarce on the waters surface. But one note of caution: This plant may take over the world if allowed. Its invasive as all get out, so keep it under control or you (and your neighbors) may wish youd never laid eyes on it.

Submerged plants, such as Cabomba, Anacharis, and Jungle Vall, not only produce oxygen for use by both plants and fish, but also absorb nitrogen from decaying plant matter and fish waste that would otherwise be used by algae to proliferate.