Most pond owners know the importance of water quality for the health and beauty of their pond and the fish that call it home — but few know how to get (and keep) their pond water clean and fresh.
Your first line of defense against poor water quality is having an adequate filtration system in place. If you think your system is too small, chances are it is. Large filters have more surface area for bacteria to colonize and grow, so they don’t have to be cleaned as often — leaving you more time to enjoy your pond.
There are four types of pond filtration — mechanical, biological, chemical and ultraviolet clarification.
In this article we’ll discuss each one so you can decide which combination is best for your pond.
How does biological filtration work?
Biological filters use natural bacteria to break down pond wastes and convert them into beneficial compounds.
The process is simple.
Fish and decaying plant material produce ammonia, which is broken down by bacteria as part of the Nitrogen cycle. This process requires the presence of two distinct groups — the bacteria that converts ammonia to nitrites and the bacteria that convert nitrites to nitrates.
This is a vital process, since both ammonia and nitrites are toxic to fish and aquatic plants. Nitrates can be used to fertilize aquatic plants, which also help to filter the water.
It’s important to keep the nitrate level balanced — if you overstock your pond with fish (creating excess ammonia) or don’t have enough plants to use up the nitrates your pond will soon be taken over by unsightly algae growth.
A good biological filtration system relies on two things — a surface for the bacteria to colonize and grow and flowing water to supply them with oxygen and nutrients.
The more surface area a filter has, the more bacteria it can support — which results in better water quality.
Is chemical filtration harmful to fish?
Chemical filtration uses activated carbon (charcoal) to neutralize pollutants such as tannin, odors, and chlorine in pond water — so it’s not harmful to your fish or your aquatic plants.
Chemical filtration can be used in conjunction with a 2-stage system (mechanical and biological) to create a 3-stage system — eliminating natural chemicals that can’t be removed by mechanical or biological systems.
These filters are only effective for a short period of time and should be replaced regularly.
How does ultraviolet light help filter pond water?
The primary function of Ultraviolet (UV) light is to reduce harmful bacteria and destroy single cell algae that forms on the surface of your pond.
Keep in mind, however, that while UV light will give you clear water, it doesn’’t actually filter it. You’ll still need to include a biological filter to break down the ammonia and dead organica (including the algea killed by the UV light).
UV clarifiers can be added to existing filtration systems for additional support, or be integrated into the filtration products themselves.
Looking for a low-maintenance pond experience?
Ponds are beautiful yet delicate ecosystems. Having the proper filtration systems in place — along with a variety of aquatic plants — will give your pond the balance it needs to thrive.
If you’d like help managing your pond and keeping it healthy, give the team at Raymar Landscapes a call — they’ve all been trained by Aquascape, North America’s leading manufacturer of water gardens, water features and ecosystem ponds.
You’ll be free to watch the fish swim under the lily pads and let the sound of the water relax you and nourish your soul — without having to worry about keeping the water clear and healthy.