Daphnia
By Carol Sindelar

I remember when I was young and we would play with the guitar, my dad would recommend tuning it with a little phrase, “My Dog Has Fleas” Now I tune my pond with:

“My Pond Has Fleas”

I tune my pond with “ditch fleas” or “water fleas”, Daphnia pulex. This wonderful little creature is a crustacean native to waters all over the world. Not really a bug at all. But when I talk about all the “bugs” that inhabit my pond, Daphnia is one of them.

Why do I want Daphnia in my pond? First off, they have a voracious appetite for “Green Water”. Yes, that pest of the ponder, water born, green algae, thick as pea soup. Daphnia eats the algae that creates the green pond. Secondly, Daphnia is food for my fish. First food for baby fish in the spring. A treat for all of my fish most of the year. Daphnia ...... bon -appetite. So if we look at this as a cycle, Daphnia eats green algae, Fish eat the Daphnia, Fish expels Ammonia as waste from eating, Ammonia feeds the algae, Daphnia eats the Algae. Mother Nature at her best.

If the Ponder doesn’t get in the way, Daphnia will eventually happen naturally within a pond. Usually after the pond has turned green, very green. And it can be a long slow road back to clear. And I, like most ponders, am inpatient. So I imported Daphnia into my pond soon after the fish were added to allow them to get going right along with the green water, not allowing the algae to take over.

How does one “tune” the pond with Daphnia? By going to any natural area that has standing water and harvest some daphnia. A bag, a fine mesh net, patience and a knowledge of what you are looking for is all you need. The photo gives us an idea of how they look, but Daphnia are only the size of a pin head. They are red, or brown, or rust, or green or clear. The females are larger then the males. And they are not alone in the water. There are a lot of other “bugs” in there that you may or may not want in your pond. Finding Daphnia can be a challenge.

So how does the ponder get in the way of Daphnia setting up a great colony in their pond. Several ways. Chemicals to kill algae. OK, I hear you saying the label says it is safe for everything in the pond, except the algae. Well yes it is. But the side affects can be bad. Lets look at what happens when we chemically treat green water. First, we kill the algae. Hurray, instead of having live green algae which is removing ammonia and producing oxygen, we have dead green water algae. Dead green water algae is still in the water. It is decomposing in the water. It is creating additional ammonia as it decomposes. Like having a dead fish in the water. The high ammonia/nutrients are feeding any green water algae that was not killed. “It’s back”. Along the way the fish are stressed, more ammonia. The Daphnia are depleted. The natural cycles are disrupted. If treating with chemicals, always do water changes to remove the dead algae.

Another note about chemicals. Those with Copper in them will kill Crustaceans, and Daphnia is a Crustacean.

Another thing ponders do that gets in the way is, over clean the pond. I heard a lot of this during a pond tour of non-owner build and maintained ponds. The caretaker drained and “power washed” all of the ponds surfaces, rocks, bottom, etc., every fall and every spring. Washing away all of the “good things” in the pond. In the fall the Daphnia drop frost-resistant eggs that are attached to all of the surfaces of the pond, waiting for spring. When the water warms up they hatch, multiply, ready to feed the baby fish that are spawned in the spring and eat the algae as soon as it starts growing. Isn’t nature wonderful. Green water will always happen. Just put a glass of water in any sunny window. Add some lettuce or other leaves. In a week or two, green water algae, green water. If we wash most of the Daphnia eggs away, we are starting our biological over at square one every spring. Killing a friend whom we are allied with against the algae. But hey, if we keep the biologicals of the pond retarded it keeps Pond Maintenance companies in business.

Tune your pond by being in tune with what else is living in there besides the fish and plants and begin to understand how they all work together. Working with Mother Nature, not against her.