| Once you know the volume of water in your | | | | however; they can be very expensive to |
| pond you can start to consider your options. A | | | | purchase; the beads will after a period of time |
| word of caution here! Please be aware that a US | | | | clump together in what is known as channeling. |
| gallon is 3.7854 liters, whereas an Imperial gallon | | | | This reduces the effectiveness of the beads in |
| (UK gallon) is 4.54609 liters. This issue may need | | | | oxidizing ammonia and will require a back flush to |
| to be considered when you are looking at product | | | | break up the solid mass of beads and pond |
| specifications for imported products. | | | | waste. Occasionally some of the tiny beads break |
| What Are The Most Common Pond Filter Types? | | | | and become lodged in the internal laterals of the |
| * Pressurized pond filters have over the last 10 | | | | filter unit. In the USA the leading bead filter is the |
| years or so started to dominate the pond | | | | Aqua Ultima range by Aqua Ultraviolet. Other |
| keeping market, particularly in the small to | | | | popular models are the Aquadyne range by Koi |
| medium sized pond category, which is the | | | | Camp Aquariology, the Aquabead and Biotek |
| category the vast majority of pond keepers fall | | | | range by Grand Champion Technologies (GC Tek) |
| into. The reason for the success is due to: their | | | | and the Challenger and Econobead filters by |
| outstanding reliability; the compact, space saving | | | | Fluidart Technologies. Some of the models are |
| design; the pressurized operation that allows the | | | | supplied with a lifetime warranty. |
| filter to be placed away from the pond, out of | | | | * A gravity fed pond filter needs to be installed |
| sight and the fact that the water leaving the filter | | | | adjacent to the pond, and at the same level. Pond |
| is still under pressure which means that it can be | | | | water is fed into the system via a bottom drain. |
| used to supply a water feature or waterfall. | | | | This multi chamber filter incorporates a pump in |
| Another major advantage is the inbuilt back | | | | the final chamber that forces water back into the |
| flushing system which allows waste matter to be | | | | pond under pressure, often via a venturi. As a |
| expelled from the filter, simply by pressing a | | | | result the pond surface will always be slightly |
| button or turning a handle. This makes routine | | | | higher than that in the filter, causing water to |
| cleaning easier. The three best choices in my | | | | pass through to the filter via the bottom drain |
| opinion are the Fishmate Powerclenz pressurized | | | | under gravity. This type of bio filter is tricky to |
| filter range, Hozelock Bioforce range and the Oase | | | | install and is usually used in large Koi ponds. A |
| Filtoclear models. All three brands are supplied with | | | | vortex Koi filter is an example of such a system |
| excellent warranties (5 years with Oase) and | | | | and is the preferred filtration system in the UK |
| have been engineered to keep running costs to a | | | | and in Japan, the ancestral home of Koi. The |
| minimum. If you are looking to prevent green | | | | major advantage of a vortex filter is that waste |
| pond water then look at the integrated UV | | | | matter is not able to come into contact with the |
| clarifier models. | | | | nitrifying bacteria. This helps to ensure better |
| * A gravity return filter, also known as a gravity | | | | pond water quality and less opportunity for |
| discharge filter is probably what the vast majority | | | | heterotrophic bacteria to pollute the pond and |
| of us think a pond filter looks like, if we were | | | | cause fish diseases. |
| asked to describe one. These rectangular box | | | | What Factors Affect Pond Filter Choice? |
| type filters are still extremely popular, throughout | | | | The choice of pond filter type is dependent in the |
| the world, despite loosing some of their market | | | | most part upon the volume of water in your |
| share to the pressurized pond filter variety, over | | | | pond and the number and type of fish stocked. |
| the last decade. The major advantages of this | | | | As a rule of thumb if you have a pond up to |
| type of pond filtration system are the low initial | | | | 1000 US gallons I would recommend either a |
| purchase cost, the ease of installation, the | | | | gravity discharge filter or a pressurized pond filter, |
| availability of different models and because the | | | | as the larger Koi pond filter systems would be far |
| design has been around for so long, most of the | | | | to expensive for your needs and would also be |
| kinks have been ironed out. This submersible | | | | over kill. These larger Koi pond filters are better |
| pump fed system relies on a pond pump to | | | | suited to use in large Koi ponds where there are |
| power pond water to the filter, where it is purified | | | | large volumes of water, ammonia and solid waste |
| of debris and ammonia before flowing back into | | | | matter. When looking at a particular brand, take a |
| the pond under the influence of gravity. For this | | | | look at the manufacturers website where you will |
| reason it needs to be positioned at the highest | | | | often be able to find downloadable user guides |
| point of the pond. I would recommend the | | | | and installation manuals. |
| Fishmate gravity return filter because it is supplied | | | | Retailers will often advertise big filter models for |
| as standard with Supra bio media (Alfagrog in the | | | | big ponds and smaller models for smaller ponds. |
| UK). This low cost filter media encourages large | | | | On the whole this is a marketing ploy as it is not |
| colonies of ammonia oxidizing bacteria to colonize, | | | | the size of the filter that influences its |
| ensuring that ammonia is removed from the pond | | | | effectiveness! It is the size of the bacteria colony |
| water quicker than it would be if plastic coils or | | | | available to break down ammonia, along with the |
| lava rocks were used. | | | | availability of oxygenated water allowed to mix |
| * Fluidized bed filters, more commonly known as | | | | with the bacteria. Remember that the single best |
| bead filters are professional pond filtration | | | | way to improve biological pond filtration in gravity |
| systems aimed at pond owners with large ponds | | | | discharge filters and pressurized filters is to use a |
| and large fish loads, particularly Koi. The secret to | | | | filter media with a high surface area, as this allows |
| the effectiveness of a bead biofilter is the design; | | | | more nitrifying bacteria to colonize. It is a |
| the biological chamber is home to upwards of | | | | numbers game! The more bacteria available, the |
| 500,000 tiny beads that are suspended in water in | | | | quicker ammonia will be broken down. In addition a |
| a pressurized environment. The violent thrashing | | | | biomedia with a higher surface area means that |
| together of fresh water, oxygen, beads and | | | | you will need less of it, which means that you |
| ammonia (NH3) provides the best possible | | | | physically need a smaller filter in which to store it. |
| scenario for quickly and efficiently breaking down | | | | Supra pond filter media is an excellent low cost, |
| ammonia. There are some disadvantages | | | | porous product with a high surface area. |