by: Mark Washburn
When the warm weather of summer finally arrives most pond owners are faced with a very common problem called pond algae. Pond algae can strike any size pond at any time, but usually a few very specific things have to be present for it to spread rapidly.
Knowing what allows algae to prosper is the first step to treating it naturally. First though, let's make one thing clear. Algae, or it's presence in a pond is not always bad. A little bit of it here or there is actually a positive sign that the pond is healthy and balanced. When algae takes over the pond entirely however, things are not very balanced at all.
Algae is very dependent on excessive nutrients in the water to grow. Therefore this should be your first priority...to reduce or eliminate excess nutrients in the pond. These can come from decomposing organic matter like leaves or grass clippings.
Nutrients can also come for fish waste or decomposing fish food. With these things in mind, it's best to remove any organic matter from the pond before it starts to decay at the bottom. Skimmers can help with this in smaller ponds. Also, if you have fish, be sure to not overstock them in a smaller pond. Generally 1 inch of fish needs about 10 gallons of water to stay balanced. If your ratio is over this, you may be overstocked. Be sure to not overfeed your fish as well. Provide them enough food to consume in about five minutes time.
Pond algae also needs adequate sunlight to grow aggressively so if you can minimize exposure to the sun, this can often help.
In some cases, you can't always keep sunlight from entering the pond or keep all the debris from settling in it. Then it's often best to turn to other treatments or options.
In smaller ponds adding plants is a very beneficial thing to do. Surface plants like water lilies help absorb excess nutrients and also help shade the pond. Water grasses are great at helping clear a pond as well.
Since it can take up to 60% coverage of a pond's surface to keep algae at bay, some people like to also use a natural beneficial bacteria product to help consume some of the excess nutrients and assist in the breakdown of organic matter in the pond. Bacteria and enzyme products have been proven to be one of the safest and most effective ways to keep a pond clean. There are many varieties available on the market today.
All of the methods outlined above are highly preferred over using chemicals in a pond or water garden. Chemicals come with inherent risks and also don't help much in cleaning a pond in a natural fashion. Over the long term they can cause many more problems than then solve.