The Aquarium 25 



is necessary. If this is not provided for, 

 the fishes will die of suffocation. Of the two 

 ways to improve the conditions in the aqua- 

 rium, new or additional vegetation is by far 

 the cheapest and easiest remedy of the evil. 

 It is worth considering that vegetation is 

 most active and vigorous in spring and the 

 aquatics form no exception to this rule. 

 There is therefore a certain advantage in 

 arranging an aquarium in the spring, when 

 within a few weeks the plants will be firmly 

 established and fairly fill the space allotted 

 to them, but there is no objection to begin- 

 ning the work at any time regardless of the 

 season, as long as the material can be ob- 

 tained. The only difference is that during 

 fall and winter the rooting and spreading of 

 the plants may take a little longer. 



THE WATER. 



It is of the greatest importance for the 

 well-being of vegetable and animal life in the 

 aquarium to make use of the right kind of 



