FILTERATION (Contd.)
AQUARIUM CARE Filteration (II) Filteration is, without doubt, fundamental to successful fish-keeping. Any consideration of the topic of filters is complicated by the fact that there are almost as many types as there are days in the year. In the case of the internal filters, the cheapest are more or less the best. Having discusses about the maintenance-free under-gravel filter last time, we shall focus on the commonest alternative internal filter which is called the BOX FILTER. All box filters operate on the same principle, that of passing the water through a disposable medium of one kind or another. Some of the common media used are filter-wool, carbon, gravel, etc. In the case of the filter wool it must be appreciated that I am not referring to ordinary cotton wool, which would, if used, result in heavy organic pollution, but to a special non-organic material made from synthetic fibre. Of all the media, activated charcoal is the best type, this would produce ...