The Aquarium 27 



the bottom should not be disturbed. To 

 prevent this, a waterglass, or other similar 

 vessel, may be placed in the aquarium on 

 the side where the gravel is lowest. In this 

 the water is poured slowly and carefully 

 until it reaches about half the height of the 

 aquarium. Now the glass may be removed 

 and the filling can be continued up to 

 the proper height, but even now the water 

 should not be poured in with too much force, 

 as it will often disturb the gravel and wash 

 out the newly set plants. To effect the fill- 

 ing without any disturbance of the contents 

 of the aquarium, a simple implement, the 

 filling tube, can be used. Should the water 

 appear slightly cloudy after the filling, one 

 or two days, or in smaller vessels even 

 a few hours, will be sufficient to effect a set- 

 tling of all floating impurities, so that it is 

 absolutely transparent. If the aquarium is 

 properly stocked with fishes and plants in 

 the right proportion, a partial renewal of 

 the water and a cleaning out of the sedi- 



