Post by Cyberguppy on Jan 29, 2006 20:40:01 GMT 10
External Cannister filters are usually used on larger tanks (65Lt plus) because they provide much more surface area on the inside and also through the media used inside (ceramic noodles/bio balls) for beneficial bacteria to grow on. they usually also have several compartments in which you can add zeolite, charcoal for chemical filtration or sponges and wool for fine mechanical filtration although most filtration is done by the bacteria living in the filter media inside. specialist cartridges such as peat can also be bought for different aquarium needs. with these it is usually best to get the next size up than reccomended (if you can afford it) for optimum filtration.
