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THE GUIDE TO NATURE. 



Under the Auspices of The Aquarium Society of Philadelphia, Herman T. Wolf, Editor 



Water for the Freshwater Aquarium. 



Questions as to what kinds of water 

 are best for the household aquarium 

 are so frequently addressed to the 

 writer that some little elucidation on 

 this subject may be of general inter- 

 est. 



The fishes which best survive under 

 these necessarily artificial conditions 

 are the common forms of the pond and 

 stream and the domesticated golden 

 carp or goldfish and its variants, pro- 

 duced by selection and breeding. The 

 most of these are natural to any still 

 or slow-flowing water, and it is the 

 Cyprinidae or carplike fishes which 

 survive the longest in the aquarium, 

 as they require less oxygen, dissolved 

 or held in suspension in the water, 

 than those whose habitation is cold 

 water or the swift running brook. 



Therefore, any water fit for drink- 

 ing or culinary purposes is all that is 

 required for the usual aquarium fishes ; 

 but cold-water fishes require larger 

 containers and a constant change of 

 water admitted under pressure, or else 

 some means of artificial aeration to 

 suoply sufficient oxygen. 



It is an erroneous idea that water 

 purified bv a mechanical filter is in- 

 jurious. Some inquirers ask whether 

 filtration will remove food for the 

 fishes. Only very few of the low forms 

 of animal and plant life are present 

 at any time, and these are insufficient 

 to sustain the lives of fishes, making 

 feeding necessary to their survival. 



Filtration by mechanical means is. 

 if anything, beneficial, as it removes 

 the snores and larvae of parasites and 

 other natural enemies, and when suf- 

 ficient growing plants are' present to 

 liberate oxygen and consume carbonic 



acid gas, is preferable to unfiltered 

 water, as it is clearer and cleaner and 

 will cause less sedimentary deposit 

 than the usual muddy water directly 

 from the mains. 



When filtration is aided or effected 

 by the use of alum, sulphate of copper 

 or other astringent substances, how- 

 ever, such water is unfit for the aqua-> 

 Hum and may cause the immediate or 

 ultimate death of all the fishes. This 

 was mentioned in the last issue. 

 Where such water is furnished bv the 

 city supply, it had best not be used, 

 and soft water from other source em- 

 ployed. 



Under right conditions, a change of 

 water in the aquarium is necessary 

 only at long intervals, then rain water, 

 thoroughly aerated by frequent pour- 

 ing from one vessel to another and ex- 

 posure to the atmosphere some days 

 before use, is advisable ; or spring or 

 well water similarly treated, to modify 

 its hardness. These conditions are not 

 present in many cities of the United 

 States ; and the question of the kind 

 of water for the aquarium is not as 

 important as many fanciers believe. 



Any potable water not purified by 

 chemicals is all that is required ; mis- 

 haps to the aquarium and its inhab- 

 itants can usually be traced to causes 

 other than the water supply. 



Aquarium Scavengers. 

 To maintain the balance between 

 animal and plant life, prevent the 

 deterioration of the water, remove 

 narasites, and to consume sedimen- 

 tary deposits, offal and excreta, in the 

 aquarium, scavengers are imperatively 

 necessary. These consists of molluscs. 



