THE CARE OF HOME AQUARIA 



45 



BALANCED SALT-WATER AQUARIUM. 



Sliowins- ulva and i-ecl seaAveed. 



When aquaria are newly arranged, the water may often 

 appear clouded after a few days. If the fishes show signs of dis- 

 comfort, it is due to the presence of bacteria causing the decom- 

 position of impurities introduced with the sand or from decaymg 

 plants. If the fishes appear in good condition the clouding may 

 be due to the presence of great numbers of microscopic animals 

 (infusoria) or plants (diatoms). This condition may even be 

 noticed occasionally in well-balanced aquaria, especially in the 

 spring when the water begins to warm up and particularly if the 

 aquarium is in strong light. It is best in any case to draw off a 

 portion of the water daily and add a fresh supply until the 

 cloudy condition is past. If it is due merely to the presence of 

 infusoria or other minute life, the position of the aquarmm 

 should be changed or a screen should be arranged to cut off some 

 of the light. If the fishes show much discomfort they should be 

 removed until the conditions are made right. A careful search 

 should be made for the source of decomposition. If no refuse 

 food nor decaying vegetation is found, the sand or gravel should 

 be removed from the bottom and thoroughly washed and the 

 tank sterilized. The fishes, in the meantime, may be kept in any 

 clean receptacle, and the water changed as often as is necessary. 

 After resetting the aquarium should be allowed to stand for a 

 few days, if possible, before putting the fishes in it. 



