A Backyard pond filter is an essential piece of pond equipment

Why Are Fish Pond Filters Essential To Successful Pond Keeping?

A pond filter system, essentially purifies the pond water, removing toxic chemicals produced by you Koi, goldfish, orfe and other pond fish species as part of their metabolism. Failure to control the build up of these harmful chemicals can cause your fish to become stressed, ill and in the worst circumstances die. As a child did you ever win a goldfish at a fair?. If so I'm willing to bet that you took it home and placed it in a nice new goldfish bowl, only to find that the poor thing died after a few weeks/months? Without realizing it you caused it to live in it's own toilet, where the build up of harmful ammonia and nitrites eventually caused its death. A biological pond filter also carries out other essential requirements needed for successful pond keeping, as discussed further on in this article.

Biological pond filters always work best and your backyard pond will benefit from combining the action of ultra violet light (UV which clarifies the water) with that of biological pond filtration. In this way your pond ALWAYS stays clean and clear and healthy.

Which Pond Filter Should I Choose?

If you have a small to medium sized garden pond and wish to keep small pond fish such as goldfish, small Koi, orfe etc then you really don't need to spend a fortune on a pond bio filter. Industry proven, modern gravity discharge filters and pressurize pond filter systems from industry leading companies such as Fishmate, Hozelock, Little Giant, Heissner, Blagdon and Oase will do an excellent job.

If you have a large fish pond with plenty of large pond fish, particularly Koi then you will need a biological filtration system designed specifically to handle large volumes of pond water, containing lots of waste solid matter. I would recommend one of the following specialized bead filter systems (see further down page for links) such as the GC Tek Aquabead filter range, Ultima koi filters from Aqua Ultraviolet, along with the GC Tek Biotek range and Aquadyne pond filters.

A pond filter is only as good as the pond filter media used

The table above shows a comparison of specific surface areas that various pond filter have ... the higher the better, as this will allow you to use a smaller filter to perform the same level of water purification. You can see that Alfagrog (Supra in the USA) is the clear winner. You will need has 20 times more volume of foam or 5 times more volume of Lava Rock to do the same job as a single unit of Supra ... Buying Supra contained to the other pond biomedia will not only save you money over time but will also be far more efficient at breaking down ammonia compounds.

3 Common Biological Filter Types ...

Fishmate Gravity Fed Pond FilterLow Cost Gravity Discharge Pond Filter

A common and popular choice of backyard pond filter predominantly used in small fish ponds and medium sized fish ponds. The picture on the left is a world famous Fishmate Gravity Filter that utilizes highly efficient Supra Pond Filter Media aka Alfagrog in the UK. The shape of a pond filter for the majority of small to medium backyard fish ponds doesn't matter ... the pond filter media used does!!!!  A highly efficient pond biomedia will allow you to use a smaller biofilter to perform the same water purification as a much larger filter system that uses inferior pond media, such as plastic coils.

Pressurized Fish Pond Filters

Pressurized pond bio filters have been around for a few years now and are an excellent choice for small to medium sized backyard fish ponds. Their pressurized design allows them to hidden from view, under the ground, up to the lid. Many models also include a back flushing system for easy cleaning and discharging solid waste. The example on the left is a Fishmate Pressurized Pond Filter. Along with Oase Filtoclear and Hozelock Bioforce filters they are amongst the best available to pond keepers. Pressurized pond filters are probably the dominant filter type for small to medium sized ponds, due mainly to their energy efficiency and compact size, compared with a traditional box type filter. The units require a higher pressure pump than a gravity discharge filter.

Specialized Biological Pressurized Bead Filters

These specialist Koi pond filters have been designed specifically for the Koi keeping industry and to handle large volumes of metabolic waste and water found in large Koi ponds. They utilize a biological bead filter media which has a very high specific surface area (SSA) for beneficial bacteria to colonize on.

The Aqua Ultima Koi Pond Filter system is highly recommended due to its patented biomedia. The GC Tek Aquabead Bead Filter range along with Aquadyne Bead Filters and GC Tek Biotek Filters are amongst the best available for large biological pond filtration requirements.

You Need To Know Your Pond Volume

In order to specify the correct pond filter for your fish pond it is important to know the pond volume to within 80% accuracy. A Biological Pond Filter is specified in terms of the pond volume they can handle, given normal stocking of fish. Selecting the correct filter size is important and bear in mind that fish, given good living conditions will grow. As koi and goldfish grow they produce more waste, creating more work for your pond filter ... Adding more fish to the pond also increases the bio filter workload ... always go for a bio-filter that is bigger than needed, for better performance ... Unless you are serious koi keeper with a large koi pond then a combined UV + pond filter is a better option for you in terms of cost saving.

A combined UV + pond filter serves three purposes

  • Toxin removal - An ultra violet pond filter removes the toxins (ammonia and nitrites) produced by your koi, goldfish and from decaying algae and plant life at the bottom of the pond. It is designed specifically for the purpose of removing waste and toxins from your backyard pond using the principles of the Nitrogen Cycle. Think of it this way... How would you feel if you had to eat and live in your own toilet for long periods of time with no means of opening the door and no way of flushing the toilet. This is exactly what happens to the koi and gold fish living in your pond.

  • Waste solids removal - It is designed to remove solids from the bottom of the pond, such as dead algae, vegetation etc. The filter traps them in a series of filter sponges or brushes using mechanical separation.

  • Green water control - The integrated UV sterilizer controls the levels of algae bloom (green water), parasites and bacteria in your backyard pond. Algae bloom also known as floating algae or suspended algae produces the dreaded "pea soup" effect in your backyard pond if it's growth isn't controlled. green water spreads rapidly and will eventually cover the entire backyard pond. As it spreads it depletes your pond's oxygen levels, eventually causing koi and fish deaths.

Other Pond Filter Articles That May Be Of Interest ...

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