aquatic ILitt 



little additional trouble and without in 

 any way interfering with the contents of 

 an aquarium, is the purpose of this 

 paper. 



If we have a means to restore stagnat- 

 ing, turbid or discolored water, or such 

 water as is lacking in dissolved oxygen, 

 to a sanitary state, it only remains for 

 us to guard against an unbalanced condi- 

 tion as far as dissolved mineral ingre- 

 dients are concerned, in order to be able 

 to retain our aquarium water perman- 

 ently in the best condition for fish and 

 plant life. I mention this last fact be- 

 cause it seems that even experienced 

 aquarists entertain but vague ideas con- 

 cerning this important point. One had 

 better look to nature to teach us her 

 way of keeping house as regards life in 

 water. 



The only supplementary substances 

 that ever enter a body of water, if we let 

 nature have her way, are more water, 

 rain water in fact, either directly or in- 

 directly, and whatever 'little mineral mat- 

 ter may be dissolved out of the bottom 

 or out of dry earth, this being carried 

 into such bodies of water by springs and 

 surface drainage. The wave motion of 

 the surface does the rest in maintaining 

 favorable conditions for organic life by 

 aerating the water and accelerating the 

 diffusion of foul gases into the atmos- 

 phere. The importance of these func- 

 tions to fishes becomes evident if we 

 prevent them by an impervious film of 

 oil over the water surface. 



As to the aquarium we can control 

 the character of the water put into it 

 originally, as far as its mineral content 

 is concerned, by using water of which 

 we are sure. Thereafter its character 

 can be continued nearly unchanged if 

 we replace that lost through evaporation 

 with rain water only. That is important 

 if we expect to retain our aquarium 

 water for a great length of time, for it 



may be readily seen should we replace 

 such unavoidable loss with water similar 

 to that used at the beginning, and add 

 in the course of time again as much as 

 a certain tank may hold, we have just 

 doubled the amount of solids held in 

 solution. Here I wish to caution against 

 considering newly fallen rain water being 

 harmless ; it is not necessarily so. It has 

 been proven by analysis that the water 

 precipitated during the first half-hour 

 of a storm may be charged with as high 

 as 3 per mill of sulphur dioxide, with 

 other equally deleterious substances. 

 This is especially so around industiial 

 centers. One should wait until the 

 atmosphere has been thoroughly 

 washed before collecting rain water, and 

 then it should be collected in the open ; 

 if taken from conductor spouts it will 

 contain soot and other materials. The 

 writer has seen rain water collected with- 

 out these precautions that showed a de- 

 cided acid reaction. 



It may be argued that growing plants 

 extract minerals from the water right 

 along, and there is truth in that, yet, 

 rather than upset the mineral content of 

 the water, it seems to be the better plan, 

 if the plants exhibit signs of lack of nu- 

 trition, to periodically inject plant food 

 around the roots. A concoction of dried 

 sheep manure, obtainable from seeds- 

 men, is highly stimulating when used in 

 this way, and a super-abundance is soon 

 counteracted by the incidentally increas- 

 ed microscopic life. On the other hand, 

 the mineral requirements of plants such 

 as are usually found in aquaria are often 

 over-estimated. There is probably al- 

 ways enough such matters dissolved out 

 of the bottom, where sand and stones 

 are used, to satisfy the requirements. 



Statements have repeatedly appeared 

 advising the novice, for they must have 

 been aimed at him, to add so and so 

 much salt and so often. In the case of 



