23 Fluidized bed filter

The fluidised bed filter is a passive biological filter with potentially high turnover rates and low risk of clogging.

The fluidised bed filter is filled with e.g. sand and offers a large surface area for colonisation with bacteria. The water flows from the bottom to the top at such a high speed that the sand grains are constantly in motion and biofilm layers that are too thick are continuously scraped off. This prevents the sand grains from sticking together and keeps the biodegradation process constant.

A fluidised bed filter is particularly useful for aquarium systems where there is no substrate (bare bottom), few or no live stones and no refugium. High ammonia and nitrite concentrations are prevented.

The fluidised bed process can also be operated with other filter media to guarantee maximum reaction performance.