A biological filter is part of a filter where beneficial bacteria (which is a good type of bacteria to have), grows and multiplies. This beneficial bacteria requires a lot of surface area to grow on, so the more surface area, the more room you’re providing the beneficial bacteria to grow on. When you add beneficial bacteria on a regular basis, such as Microbe Lift for ponds and water gardens less than say, 50′ x 50′ in size, or PlanktoniX for ponds and lakes larger than 50′ x 50′ in size, you’re always increasing your pond’s biological filter.
Sometimes, manufacturers make filters that provide both mechanical and biological filters. Beneficial bacteria can grow on the filter pads which can have a bit of surface area for them to grow on. Sometimes, there’s other biological media such as bio-balls, filter floss, bio-tubes, bio-beads, etc. for the bacteria to grow on. These are all pluses. The one thing to note with biological filters is that the more surface area the biological filter offers, the clearer your pond may be – at least in some cases. Most manufacturers clearly advertise the amount of surface area their particular filter offers. Make note of this number but know that it’s only part of the equation when it comes to keeping your pond water clear. There are many other factors such as:
. the quantity and size of your fish you have in your pond
. what size your pond is
. what size of filter you have
. what size of pump you have
. if the pond is in full sunlight or part shade
. how often the water is changed
. other chemicals added to the pond
. how often the water is filtered
. if you use a UV clarifier or UV sterilizer
. if you add fresh water to your pond on a consistent basis
. what your pond is made out of
There are many different types of pond filters. Some are gravity fed filters, meaning they should be installed ‘uphill’ where the water flows from the filter down into the pond. Other filters may be submersible and can be located within the pond itself. Some have built-in UV lights that can kill the majority of bacteria, fungus, viruses and floating algae cells while others do not have built in UV (ultra violet) lights.
The rule of thumb is to have a filter that is large enough to filter the entire body of water every 3 hours. For instance, if you have a pond that is 9,000 gallons, your filter should be large enough to filter 3,000 gallons every hour. Do know, that this is not always the case. Other factors that affect the size of pond filter you have is: the quantity of pond fish you have, if you’re adding beneficial bacteria on a regular basis such as Microbe Lift or PlanktoniX, if your pond is in full sun, what chemicals you’re using or how often you’re doing a water exchange, etc.. All of these things will affect the size of pond filter you have. When in doubt, always go with a larger pond filter than what you think. Ideally, the pond filter should filter out the total volume of water in the pond every 3 hours. So, if your pond holds 9,000 gallons, your pond filter should filter out 3,000 gallons every hour.
Your pond filter is the number one most important thing for your pond. It will be the very thing that brings you enjoyment to your pond by having good water clarity or that which brings you stress and disappointment. Don’t skimp on your pond filtration. Only you and your pond will benefit from having the right size of pond filter for it.
There are a variety of pond filters to choose from. Check out PondSolutions.com for pond filters, pond filter media, filter pads and thousands of other pond supplies besides a lot of good information on building a pond and keeping it well-maintained.
