Home » Information » 09.Pond Filter Media

00. Company Details 01. Terms & Conditions02. Koi Help03. Japanese Terms031.Koi Markings Variety
04. Breeding Koi05. Water pumps06. Air Pumps07. Discs/ Diffusers08. Pond Filters
09.Pond Filter Media10. Other Water Filters11. Skimmers12.Skimmer Guards13. BottomDrains and Accessories
14. Koi Handling Tanks Bowls Socks15. Pond Maintenance Vacuum Equipment16. Ozone17. Ozone F.A.Q.18. Pipe and Pipe Fittings
19. Chemicals Pond / Koi21. U.V. Steriliziers Clarifiers22. Heating23. Koyoshi food and Treats

  Product Evaluation and testing ..........Filter Media


In simple terms the pond filter contains media on which a large amount of specific bacteria grow. These bacteria are required in order to digest the pollutants created by fish bodily wastes building up in the pond water. Think of the bacteria as clinging to all possible surfaces in the pond filter box. This means the more surface there is then the greater the space for the bacteria to cling to and the more the amount of bacteria there can be.

Illustrated imediately below are two of the most popular types of modern Polyethlene (PE) media available.

Illustrated above is the ployethlene (PE) Bead media as used in all modern bead filter applications.

To the right above Is our very own Biocel media. Not much to say here in so much as we are all familiar with this type of media.


Material - Polyethylene (PE)
Specific Surface Area - 198 ft2/ft3 (650 m2/m3)
Maximum Fill - Up to 75%
Weight per m3 - 128 kg/m3
Number of units per m3 - 1,260,000
Surface per unit - 5.12 cm2
Percentage of hollow space - 95 %
Color Natural - white

Polyethlene (PE) beads

With Beads A question often asked: Is there a conversion from Weight (kg) to Volume (Ltrs)

Answer: Because of the slight variation in size and density of polyethylene (P.E.) floating beads there is no direct conversion. 25 kg will be somewhere between 35 and 40 ltrs If you were to work on an average of 7.5 ltrs / 5kg. you wont be far out. Another conversion factor we use is 7-8 kg. / 1000gls of pond water.


Activated Carbon


Used as a filter in a vessel through which water is pumped, the pellets are most effective in removing organic contaminants which are often responsible for odour and colour problems. Particularly useful in removing chlorine from mains water. Activated carbon will not, however, remove nitrates, fluoride and hardness. ___________________________________________________________________________________


For more information and Different types of Media for Please click here

For latest on our own Range of Beed filters for More info please click here



Vortex chambers are good for settling out heavy waste but much less efficient with the lightweight particles. Have you noticed that even though you get a lot of waste in the bottom of your vortex, you still find that the subsequent chambers get very dirty too. This is the very fine particles that do not have time to settle in the vortex and so they get drawn through the transfer port into the next chamber.

How do they work?

Black Knight brushes work in three ways. First, they physically trap the large particles that cannot pass through the close weave of the interlocking filaments. Secondly, the filaments have a static charge that ?grabs? any small particles that are flowing by. This charge holds onto the waste until you do your routine cleaning. Thirdly, after you have been using the brushed for a few weeks, the massive surface area of the brushes becomes home to millions of beneficial nitrifying bacteria that will help to purify your water biologically.

How do I use them?

Simply insert a vortex brush in the path of the flowing water and you will be amazed at how much waste is collected in a short time. If your second and subsequent chambers are already full of media then you can use either one vortex brush strategically placed around the transfer port or you can use several to build up a barrier of them above the inlet of the vortex and below the outlet (assuming that your vortex is designed in this way). This will allow the heavy waste to drop to the bottom of the chamber and then all the waste that does not settle is forced to pass through the brushes thus allowing it to be caught.

You can coil one or two vortex brushes around the outlet so that the water has to pass through the brushes.

You can create a complete barrier filling the whole cross section of the chamber. With the more brushes you use, the greater the amount of waste that can be collected and also the larger the surface area for biological filtration

Vortex brushes can be used in as many chambers as you wish. It is a good idea to leave some room in the first chamber to allow for settlement but subsequent chambers can be filled with vortex or filter brushes as shown.
How do I maintain the filter?

The frequency of cleaning will depend upon the size of the filter relative to the pond size and also the loading on the system i.e. the bodyweight of fish in the pond, how much they are eating and how much dust and plant debris is being produced.

The rule of thumb is - the more often you do your cleaning, the cleaner your pond will be. On a lightly loaded system then once every three weeks in the warm months may be sufficient but twice a week may be necessary on a heavily loaded system.

Brushes can be cleaned in-situ if you wish. Simply drain the chamber and then rinse the brushes by pouring buckets of pond water over them. Alternatively, you can take the brushes out, clean and then replace them.

You can use chlorinated tapwater for cleaning them but you will temporarily reduce the biological effectiveness of the brushes with this method.

Basket total: £0.00

Shop Departments