Goldfish are the world's most popular pet so understandably associated with coldwater aquariums; however people often neglect to acknowledge the diverse and varied selection of coldwater specimens available. When stocking the aquarium it is beneficial on both a biological and aesthetic level to replicate as near as possible the natural order of things. This consists of ensuring there are top/middle and bottom feeding stock. Top feeding fish such as goldfish float around, usually towards the top half of the aquarium producing waste that collects on the aquarium bottom. By selecting to keep coldwater members of the loach family (weather and stone loach) you will have bottom dwelling fish that disturb decomposing sediment on the aquarium bottom, accelerating the biological cycle and filling the bottom part of the aquarium. Koi carp although they are cold freshwater specimens are not particularly suited to aquarium environments. As tempting as it is to keep them they require vast filtration, due to the amount of waste they excrete, and a large stable aquarium due to the natural size of the fish and their inability to deal with changing water quality.
The recommended stock for a coldwater aquarium for tanks less than 50 litres is common goldfish, comet, shubunkins, moor, oranda, ryukin and fantail, weather and stone loach. They are all relatively tolerant to fluctuating conditions, common in smaller aquariums. Larger aquariums can house all above specimens and those less tolerant to change in conditions including sailfin sucker, perch, pike, spotted gar, bowfin, tiger loach, medaka, dwarf topminnow, westen mosquitofish, white cloud mountain minnow, rainbow darter and bullheads. Please call for further information on these fish and their availability.
Hong Kong Plec