Green water in your garden pond?

ne way is with water plants. Experienced water gardeners store stock up on annual pond plants early in the year; “floaters” like water lettuce and water hyacinth.

These plants multiply rapidly on the pond surface, forming a living “umbrella” that casts shade on the water. Perennial water lilies are also very helpful in keeping sun from warming pond water.

By August, vegetation should cover most of your pond’s surface.

Ponds in direct sun all day are the hardest to manage. You can use plantings along pond banks, particularly on the southwest side, to shade the water during the hottest part of the day.

Overhanging shrubs and ornamental grasses work well, and so do trees. There are lots of perennials that thrive along pond banks or in shallow water. These plants are called “aquatic marginals,” and many of them are perennials that will come back each year.

In addition to making a natural appearance, they help create a balanced environment around ponds that helps control algae.

Keeping water rapidly moving is another important aspect to controlling “green water” in your pond. Waterfalls and fountains mix in fresh oxygen to keep water from becoming stagnant. Rapidly moving water prevents “hot spots”, mixing cool subsurface water constantly.

To prevent “hot spots”, water should circulate completely from one end of the pond to the other, twice each hour. Make sure your pump is sized large enough. A 1000-gallon pond should have at least a 2000 gallon-per-hour pump (or larger if the pump “lifts” water up a hill or to a waterfall).

To prevent “hot spots”, water should circulate completely from one end of the pond to the other, twice each hour. Make sure your pump is sized large enough. A 1000-gallon pond should have at least a 2000 gallon-per-hour pump (or larger if the pump “lifts” water up a hill or to a waterfall).

Rocks and pebbles equalize the night and day temperatures, cooling the water by day and warming it at night. Gaps between stones give fish a place to hide from predators, and act as natural filters by harboring beneficial bacteria.

A healthy living pond environment provides enough food for goldfish and snails, who help keep the pond clean. Fish wastes, in turn, help feed pond plants.

Overfeeding of fish is a major cause of algae bloom in water features. We stock our pond with bait goldfish, and never add fish food of any kind.

The fish thrive by eating mosquito and frog eggs, tadpoles, algae and insects, scrubbing the pond naturally.

Every water feature has “issues” with string algae, particularly during the summer months. We recommend fish-safe, plant-safe algae control products like AlgaeFix and barley straw, and use them in our own pond, but they are only one ingredient in a successful “recipe” for clean, clear water.

These elements create a healthy environment similar to natural stream beds, where plants, insects and animals live in harmony in clean, clear water.