Probably the most common complaint we hear from pond keepers is that their ponds are green or dirty.
The probable cause is more than likely algae. There are over 25,000 known varieties of algae and they exist all over the world in oceans, rivers, lakes, streams, ponds, marshes and aquariums.
Algae will turn a new pond green after a few days depending on the temperature and sunlight available. The algae will thrive on the dissolved mineral salts found in fresh water, so emptying the pond and starting all over is not going to keep your pond from going green.
Algae can be airborne or carried into your pond by birds that drink or bathe in your water.
Algae is actually good for your pond. The algae will break down wastes in the pond and digest them to keep the water quality up. The algae oxygenates the water and many serious koi keepers have found that if they place their koi in a “green pond” several months before a show the colors are stronger and more vibrant.
The fish are perfectly happy and thrive in green ponds. They are safer from predators too, as the predators can’t see them.
