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Filter systems can be purely a matter of personal prefernce. I have for many years favoured the use small box filters in all my smaller breeding tanks. They are generally cheep to buy and easy to maintain. More recently though I have taken to using a wider range of sponge filters to replace the box filters.

Box filter

Box filters work very well in the smaller breeding tanks and easily maintained, they can also be filled with moss peat or other water conditioning agents.

Small sponge

The "Poly filter" has been a favourite of mine for many years and are used in small fry rearing tanks.

Free standing sponge

Most of these are either 10 cm square by 5 cm deep or 10cm cubes and have a weighted base to help them hold position on the bottom of the tank. There are many adaptations to the basic system, which is to draw water at a steady rate through a piece of sponge to remove suspended particles, fish waste. It takes a little time for a new filter to mature and become colonised by nitrifying bacteria, but once mature are very efficient.

Sponge Matt filters

As of December 2012 I have changes all my free standing sponge filters to the type of filter that has been used by German aquarists for many years. The system was first devise by aquarists in Hamburg and has been know as the 'Hamburg filter' ever since. The German aquarists themselves refer to it as the 'Matten filter' because that is exactly what it is. These filters are very efficient and are very low maintenance. Click on the link for an indepth look at the 'Hamburg Matten Filter'

Canister filter

For the larger stock tanks I used to favor outside canister filters, although each tank now (December 2012) has full width "Matten" filters.

Canister filters come in all shapes and sizes, with varying flow rates, again these are all a matter of choice. I prefer the Eheim Ecco range, of which there are three basic sizes, a two, three and a four chambers. One of the reasons I like these filters as well as there efficiency and reliability, is because they are equipped with a handle, making it easy to hang them near to where they are needed. All the filter inlet pipes are situated behind the "Matten" filter sponges, so the actual flow rat is increased.