Hozelock/Cyprio World Famous Green Machines conventional biological pond filters for fish ponds
Pond Filter Clean Water To Allow Fish To Survive in Their Own Pollution
The
simplest of all pond filters is the “black box” type. The Hozelock Green
Machines handles ponds up to 27,000 litres in volume (and that's a big garden
fish pond).
The Green Machine uses open cell foam and brushes used to mainly remove leaves, and larger particles of whatever can get into the pond filter. It has a limited amount of biological capacity
Plastic biomedia on which bacteria accumulate is used in the Green Machine by Hozelock/Cyprio
WARNING bio filters do not clear green or murky ponds as many people claim. To ensure a clear pond an UVC is needed ... this kills suspended algae which can then be removed by the bio filter. While still living algae are very very very tiny and just pass straight the pond filter. In other words for a crystal clear garden fish pond you need BOTH a bio filter and an UVC or ultra violet clarifier
The simplest homemade pond filters contain almost anything you can imagine from hair curlers to gravel.
BUT ... if it was me and because I'm a bit ham-fisted I would buy a box filter or a Hozelock/Cyprio Green Machine for larger ponds like this one above and shown in table below ... Hozelock produce a wide range of pond pumps to satisfy any size pond
| Hozelock pond filter model | Pond max volume litres | Maximum water flow lph | UVC needed for CLEAR water |
| Hozelock Ecocel 2200 | 2200 | 1100 | Hozelock Vortron 2200 |
| Hozelock Ecocel 4500 | 4500 | 2250 | Hozelock Vortron 4500 |
| Hozelock Ecocel 9000 | 9000 | 4500 | Hozelock Vortron 9000 |
| Hozelock Green Machine 6500 | 6500 | 3250 | Hozelock Vortron 9000 |
| Hozelock Green Machine 9000 | 9000 | 4500 | Hozelock Vortron 9000 |
| Hozelock Green Machine 11500 | 11500 | 5750 | Hozelock Vortron 14000 |
| Hozelock Green Machine 16000 | 16000 | 8000 | Hozelock Vortron 18000 |
| Hozelock Green Machine 18000 | 18000 | 9000 | Hozelock Vortron 18000 |
| Hozelock Green Machine 23000 | 23000 | 11500 | Hozelock Vortron 27000 |
| Hozelock Green Machine 27000 | 27000 | 13500 | Hozelock Vortron 27000 |
| Remember a biofilter CLEANS water and an UVC (Ultra Violet Clarifier) CLEARS water | |||




