22 AQUARI UM MANAGEMENT 



surface of the water free of dust or bubbles, prevents objects from acci- 

 dentally falling into the aquarium, keeps the fishes from leaping out and 

 our friend the cat from fishing in. Wire gauze, properly secured, will 

 serve the latter purposes. 



With most tropical fishes the glass cover should rest directly on the 

 aquarium or jar, with no intervening space. This keeps the water a few 

 degrees warmer. Furthermore, there are a number of tropical fishes which 

 can leap through a very small opening. This they are most apt to do 

 when newly placed in an aquarium or otherwise disturbed. Our wild 

 native fishes have an increased tendency to leap as the breeding season 

 approaches, this characteristic being shared by the single-tail goldfishes. 



Artificial Aeration. With the idea of adding to the oxygen-content 

 of water, particularly at night when the chemical action of plants is 

 negligible, some of our more ambitious aquarists install an air pump 

 which is piped to each aquarium and there air is liberated in fine bubbles. 

 This scheme to some extent counteracts the evil effects of overcrowding. 

 It tends, however, to agitate and circulate aquarium sediment. Elec- 

 trical pumps are the most satisfactory. Complete outfits are usually 

 advertised in the magazines listed after our Bibliography. 



Testing Aquaria. Before putting plants or sand in the aquarium 

 it is well to test its tightness. More often than not the larger sizes leak 

 after moving or standing dry. These leaks can usually be corrected in a 

 few days by filling with very muddy water, stirring it occasionally. 



Removing Dust and Scum. When the aquarium has no cover glass 

 or when there is a considerable decomposition of old plants there is some- 

 times a scum formed on top of the water. To remove this, tear a piece of 

 newspaper to the width of the aquarium. Float the paper at one end of 

 tank, lifting by one edge, and draw quickly over the length of the water. 

 Repeat once or twice with fresh paper. 



Foul Sand. Sometimes sand or pebbles will turn black and become 

 quite ill-smelling. The cause for this is not always easy to determine. It 

 is more apt to occur where the light is feeble and the plant growth poor, 

 also where sand is too deep. If taken out and dried in a thin layer it will 

 clear up. If the conditions seem right and there are sufficient plants, do 

 not be hasty about taking out dark sand. The condition often corrects 

 itself if given a chance, and besides, it may be just a little natural dirt 

 which does no harm. 



Algae and Confervae. Should the plants become completely covered 

 with algae or "moss," try introducing a considerable number of small 

 snails. The large Japanese variety is not always suitable for this, as it is 

 unable to crawl on the smaller leaves. If this fails, remove and destroy the 

 plants, thoroughly disinfect the aquarium in every particular and replant. 

 Do not allow quite so much light in the future. 



