Get Rid of Sludge: Organic Bottom Sediments in a Pond

Sludge is not a topic for polite conversation, is it? It’s at the bottom of every pond to one degree or another, and it’s something that you may not want to talk about. But if your pond smells and the fish are sick, you need to think about what is at the bottom of the pond.

What Are Organic Bottom Sediments?

Organic bottom sediment or sludge is a layer of what might be referred to as goop. Over the year, leaves fall into the pond. Grass clippings blow into the pond. Pond plants die and their leaves move into the pond. If you have koi or other pond fish, excess food and feces drop to the bottom of the pond. In a large pond, the feces from waterfowl and other animals can move to the bottom sludge as well. All of this makes a layer of bottom sediment.

Is Sludge or Sediment a Problem in the Pond?

If you have sludge at the bottom of the pond, is this actually a problem? In part, it depends on how the bottom sludge is impacting the oxygen levels and the water quality of the pond.

If the pond smells like rotten eggs, chances are you have a problem. This means that anaerobic bacteria are breaking down the sludge and expelling hydrogen sulfide gas. This gas smells like rotten eggs. These bacteria also release ammonia, which can be dangerous to fish, insects, and beneficial bacteria.

If the pond does not smell but you think that there may be a problem, check the oxygen levels in the pond during the day time and the evening. If oxygen levels are low, beneficial bacteria and insects cannot remove the sludge.

Removing Sludge from the Pond

It’s tempting to head out and buy a chemical product that removes everything undesirable from the pond. However, ponds have natural ways of keeping themselves clean.

Nature has a way of getting rid of sludge, and it’s called bacteria. There are beneficial bacteria that feed on organic sludge. If you find that you don’t have enough bacteria to remove the sludge, you can purchase beneficial pond bacteria.

Oxygenating a pond is a good way to help bacteria do their job. By oxygenating the pond water, a bubbler will allow beneficial bacteria to multiply and consume the bottom sludge.

Control Fish and Leaves to Control Bottom Sludge

To create a healthy pond environment, watch the inputs to your pond. In the fall, add a mesh net over the pond when the leaves are falling, especially if you have a tiny pond that might be overwhelmed by leaves.

Keep a close eye on the number of fish in your pond. If you have a high density of fish and you feed them a lot, this can lead to excessive quantities of fish waste and food waste that accumulate on the bottom of the pond. If sludge is a problem, cut back on the number of fish you have in the pond.

By creating a balanced pond ecosystem, you can help your pond control sludge the natural way. Controlling inputs to the pond and increasing its levels of beneficial bacteria and oxygen can help the pond maintain good water quality.