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Algae Control in Dams, Ponds and Lakes: A Comprehensive Guide

Algae are a group of photosynthetic microorganisms that are found in both water bodies and on dry land. They play a crucial role in many ecosystems, often ensuring oxygen levels are adequate, cycling nutrients, and providing the base of the food chain.

Like many of the microorganisms found in water bodies, algae bring positive effects and drawbacks to the aquatic ecosystems in which they are found.

In this article, we’re going to take a deep dive into algae in aquatic ecosystems, what it does, what types there are, and how to control algal growth.

The Roles of Algae in Aquatic Ecosystems

Algae is a primary producer in aquatic ecosystems. This means it forms the basis of the food chain and provides sustenance for a range of herbivorous organisms in your dam. In addition, as photosynthesising organisms, they are responsible for producing oxygen, which dissolves in water and ensures that wildlife has an adequate amount of oxygen to survive.

Different Types of Algae

Being able to identify the different algae in your dam or ornamental fish ponds can ensure that you’re using the right kinds of pond algae killer and following methods that will rid your pond water of algae altogether. While most algae don’t, some algae can produce toxins. If you can identify this kind of algae in your pond, you will keep everyone safe from the toxins.

Below are just a few of the types of algae you may find growing in your pond or dam.

Green Algae

Most algae people know of is the green kind that is usually found in freshwater habitats. Though it can inhabit marine and terrestrial habitats too, it is a commonly growing algae in dams, ponds, and other residential water bodies.

Their green colour comes from the presence of chlorophyll a and b, which helps them to store energy. Examples of green algae species include Spirogyra, Chlamydomonas, and Ulva.

Red Algae

It is unlikely for your growing algae to be red if you’re looking at a dam or pond. Red algae is usually found in deeper waters and is often associated with coral reefs. They contain chlorophyll but also blue and red pigments. Well-known examples of red algae include nori seaweed!

Brown Algae

Brown algae, like red algae, is unlikely to grow in your dam as it encompasses most of the complex seaweeds we know of. Common examples include kelp and Sargassum.


A type of microalgae, diatoms have unique silica cell walls and can be found in both marine and freshwater bodies. They make up a large portion of phytoplankton and an essential part of the food chain. They also contribute to a considerable amount of global oxygen production.

Blue-Green Algae

Blue-green algae, also known as cyanobacteria, is actually a form of bacteria rather than true algae. They are commonly found in lakes, dams, and ponds and contribute to harmful algal blooms (HABs). These algae can produce dangerous toxins, which can be detrimental to both humans and animals.

If you find cyanobacteria growing in your pond, you must take measures to get rid of it and use a method that prevents algae from returning.

  ? Buy DIY blue-green algae test kits ? —

Factors That Contribute to Algal Growth

There are actually many factors that contribute to the growth of algae, which makes finding the root cause of algal blooms and excessive growth complex in some cases. If you’re having green water problems, then any of the following could be to blame!

  • Nutrients: An excess of nutrients, like nitrogen and phosphorous, can lead to algal blooms. This is most likely to occur when agricultural runoffs or sewage discharge end up in your dam.
  • Direct sunlight: The sun is crucial for photosynthesis, which is how algae stay alive. If more sunlight than usual is hitting your ornamental fish ponds or dam, like during a heatwave or at the height of summer, there is a risk of algal growth and HABs.
  • Water temperatures: Warmer temperatures promote faster algal growth, but extreme temperature kills growing algae, too. The balance must be correct for temperatures to affect algae growth.
  • pH level: Like many organisms that live in water, algae have specific pH tolerances, and variation can have an impact on their growth. Some algae species thrive in acidic conditions, and others like alkaline conditions better.
  • CO2 availability: Carbon dioxide is essential for photosynthesis, so if there is only a limited supply of CO2, then algae won’t be able to flourish.
  • Turbidity: This refers to the cloudiness of your pond or dam water. With more suspended solids, like sediment, water clarity can be affected, which can limit light penetration. Cloudier water means less light penetration and, therefore, less algal growth.
  • Water movement: Rapidly moving water, caused by wind, water features, and currents, can affect the distribution of algae. It can cause them to disperse but also clump together.
  • Competition: As with any aquatic organism, competition within the habitat will always affect how rapidly algae grows.

When Algal Growth is a Problem for Pond Water

As a natural part of aquatic ecosystems, you’re probably wondering why anyone ever needs to reach for pond algae killer. Algae eliminator effectively controls algal growth and prevents algae from reappearing, but why would you need to do this?

  • Water discolouration: One of the main reasons people reach for pond algae killer in their ornamental fish ponds is because of unappealing green water problems. Algae can make your water turn different colours that make it disinviting to play in.
  • Algal blooms: The excessive growth of algae or harmful algal blooms creates dense layers on the water’s surface. This can hinder the growth of other aquatic life in your pond or dam.
  • Oxygen depletion: Algae may consume more dissolved oxygen through respiration at certain times of the day, particularly at night. This reduction in available oxygen can be difficult for the survival of a range of wildlife.
  • Foul odours: Decomposing algae can release strong odours into the pond water, making it unpleasant to play in or relax near.
  • Toxic algae: As we discussed earlier, some algae can release toxins in the water, which can be harmful to humans and animals.
  • Clogged filters: Algae may clog water filters, fountain pumps and more. It can also clog waterways in water bodies used for navigation.
  • Reduced recreational use: Algae discolours water and can cause it to smell unpleasant, which will make it uninviting to the kids for recreational use.
  • Poor water quality: Generally, algae reduces the overall quality of your water. Whether through discolouration, unpleasant odours, toxins, oxygen depletion or an imbalance in the ecosystem, if it grows out of control, it can cause problems.

Controlling Algae Naturally

Whether you’ve been trying to control the algae in your pond for a while, only to be disappointed when the algae reappear, or you’re looking for a way to prevent oxygen depletion after noticing issues with the plants and wildlife in your dam, we can help.

Below are our top tips for controlling algae in natural ways.

Introducing beneficial bacteria, like Biostim probiotics, into your dam can also help to reduce nutrient levels and promote a healthy ecosystem.

Installing aeration systems like fountains and bubblers, can contribute to more water circulation and oxygen levels. This supports the growth of microorganisms that outcompete algae and can prevent the growth of some species of algae

At Love My Dam, we’re advocates for natural control of algae. We believe that the best way to maintain the health of the water in your dam is to use kind and harmless methods that encourage balance and help create an ecosystem that mimics that of a natural pond.

We rarely ever suggest that our clients use chemicals to rid their dams of algae, and when we do, it is always in the most challenging cases when nothing else has worked. If you want more information on controlling algae in your dam, then don’t hesitate to contact the team today.

Final Thoughts

Algae is a natural part of an aquatic ecosystem, but it can cause problems when it grows in excess. There are plenty of natural ways to control algae populations in your dam, including the ones we have listed in this article.

For more information on the algae solutions we offer, check out our inventory now.