What is pond foam?

Seeing some foam or froth on a pond’s surface, especially around waterfalls or fountains, is not uncommon. This froth forms when water agitation creates bubbles, which can accumulate and persist on the water’s surface.

While minor froth might not be alarming, a consistently foamy pond could indicate underlying water quality issues.

Bubbles on the pond surface are often caused by dissolved organic compounds (DOCs), primarily made up of proteins. When the water is agitated, these compounds adhere to the bubbles’ surfaces, stabilising them and making them less likely to pop.

These DOCs typically result from the accumulation of organic matter that has entered the pond. There are many sources of these compounds, and with a few key pond management tips, you can prevent their build-up in the water.

The causes of pond foam

So why is my pond foamy? When organic matter enters the pond, it settles at the bottom and forms a layer known as pond sludge. Over time, this sludge breaks down, releasing organic compounds into the water. Contributing sources to pond sludge include:

(1) Overfeeding fish means wasted food sinks to the bottom contributing to sludge.

(2) Overstocking fish – excess fish excretions in a smaller space means that the pond bacteria cannot naturally process it.

(3) Blocked or ineffective pond filters fail to adequately remove organic particles and debris that will add to sludge.

(4) Decaying plant material such as fallen leaves further add to the organic load.

Using a bacterial treatment such as Envii Sludge Klear to break down sludge may initially result in increased froth due to the release of these dissolved organic compounds (DOCs). However, over the long term, reducing sludge levels promotes a biological balance and improves water clarity by lowering nutrient concentrations.

Controlling nutrient levels

To manage excessive nutrient levels effectively, prioritize controlling fish feeding practices to prevent overfeeding and minimize waste production.

Adjust feeding amounts based on fish needs and seasonal variations to maintain a healthy nutrient balance within the pond. Avoid overstocking fish to prevent overcrowding and reduce the accumulation of organic waste and associated DOCs.

Additionally, ensuring that netting is installed over the pond will stop leaves and plant debris from entering the water, adding to the waste.

Adequate oxygen levels are essential for fish health and the proper functioning of beneficial bacteria, which play a vital role in decomposing organic matter and maintaining water clarity.