Before purchasing Black Knight brushes, you should decide what type of filter design will be best for your pond.

How to use Black Knight Filter Brushes

If you have a small pond with a few goldfish and a couple of koi then a single chamber with three to six lines of brushes will be ideal. For a more demanding situation, it will be necessary to use a much larger chamber or to link two or three together. These can all contain brushes or you can use them in the first and second chambers and then use a stone medium such as Lytag, Canterbury Spar or Alfagrog in the last chamber.

Recommended spacing

The distance between the brushes should be as close to the recommended spacing as possible but the width of the chamber should be divided by the number of brushes required to give the spacing (see How Many). For instance, a 31 1/4 inch (79.5cm) wide chamber would be divided by ten when using 4 inch (10cm) brushes, to give a spacing of 3 1/8 inch (8cm) between the brushes.

How to hang your brushes

We recommend the use of 1 inch (25mm) diameter plastic pipe to make brush hangers. Standard electrical conduit is ideal for the purpose.

Slip the loops of the brushes over the pipe and secure each end either with a grub screw or a cable tie.

Using a grub screw to secure the brushes

Using a cable tie to secure the brushes

How to align Black Knight filter brushes

When you have fixed the brushes to the hangers, the other ends need to be fixed as well otherwise they will hang in a disorderly fashion.

Cut a piece of plastic about 1/8 inch (0.3cm) thick and cut it into a strip 3/4 inch (1.5cm) wide and 1 inch (2.5cm) shorter than the brush hanger. Drill holes at the same intervals as in the brush hanger; these should be just large enough to pass the wire through. Remove the knobs, pass the ends through and then replace the knobs.

These strips will hold the brushes in line and ensure that they are always held at the correct spacing.

How to fix Black Knight filter brushes to the chamber

The ends of the brush hangers can be secured using ordinary pipe clips. These can be fixed to the side of the chamber with two screws per clip. The hangers can be pulled in and out as necessary.
When using a tank of flimsy construction, it is necessary to put the clips on top of the edge of the tank and leave a little extra length on the brush hangers. This will allow for the amount the tank bows when it is filled with water.