The Inside Scoop on Pond Filtration
A good filtration system will keep your pond clean and help prevent water quality issues. Ponds that occur naturally in nature have a constant source of running water, which helps prevent algae and keeps the water oxygenated. Smaller ponds and ones that don't occur naturally need extra help to stay clear. Learn more about the importance of having a filtration system for your pond.
Closed vs. Open Ecosystems
Ponds are open ecosystems exposed to the natural environment. Leaves fall into the water from nearby plants, and when it rains, runoff from the grass carrying fertilizers and grass clippings slip into the water. Ponds accumulate organic waste that can upset the balance and affect water clarity. A closed ecosystem would be a sealed terrarium that can sustain itself.
Types of Filtration Systems
There are three main types of filtration for a pond: mechanical, biological, and UV clarification. You can find filters that combine the different types, such as a mechanical filter with a UV clarifier. Some filtration systems use an aerator to maintain water clarity and quality.
A pond pump is what powers a filtration system. Having the right-sized pump for your pond is important. If your pump is too weak, it won't filter as much as it needs to. If it's too strong, it can over-agitate the water. Learn more here.
Mechanical Filtration
In a mechanical filter, the pond pump pushes water through the filter. The filter contains special pads that catch the small debris in the water. These filters help remove fish waste, uneaten fish food, algae, and more.
You can easily clean filter pads by removing them from the filter and running them under clean water. Filter pads should be replaced completely each year. Filter pads are designed to catch small debris and should not be used to remove larger organic material (like leaves) from the water.
When using mechanical filtration, you will still need to scoop out larger debris. If you have many leaves and debris entering your pond, you could help protect your pond pump with a filter box.
Biological Filtration
Biological filters use good bacteria to break down small debris in the water. They also enhance the pond's nitrogen cycle, which is your pond's natural defense against debris. In a pond, two types of bacteria occur naturally.
Aerobic bacteria is considered "beneficial bacteria" because it effectively breaks down debris into harmless gases that release into the air or are used by pond plants. Anaerobic bacteria work much more slowly, turning the organic material into ammonia, which is harmful to pond life. Biological filters promote the growth of millions of beneficial bacteria on bio media, such as our bio-balls. As the water pushes through the filter, these bacteria work hard to break down the tiny debris.
UV Clarification
UV clarifiers use ultraviolet technology to prevent algae at the microscopic level. As the water passes, ultraviolet light kills planktonic (single-celled) algae before it is big enough to turn your water green. When algae are exposed to UV light, it disrupts their DNA and causes them to divide. They cannot survive the process and end up clumping together on the surface, ready to be scooped out.
Filtration is important for removing tiny particles of debris too small to be scooped out of the pond. Pond pumps push the water through the filters, and the debris is either trapped by mechanical filtration, broken down by beneficial bacteria, or exposed to UV light. Filtration keeps ponds clean and clear and, when combined with an aerator, ensures the water has sufficient oxygen levels. The pond's natural nitrogen cycle isn't always enough to break down debris; a filtration system gives it an extra hand.
