aquatic liitz 



81 



regarding the benefits exchanged between 

 plants and fishes has already been stated, 

 but the plants in order to do their part 

 of the work must have light — not too lit- 

 tle nor too much. They give off oxygen 

 only under the influence of light, but most 

 aquarium plants will be "burned" if ex- 

 posed to too much direct sunlight. A 

 strong north or other diffused light is 

 generally successful. An hour or two a 

 day of direct sunlight is beneficial, but 

 more than this is not recommended, par- 

 ticularly as it is apt to turn the water 

 green by promoting a rapid growth of 

 minute algae. 



Some plants are better oxygenators 

 than others. Three of the best are giant 

 Anacharis, Vallisneria, the Italian or 

 diminutive form, and Sagittaria. The 

 latter two are probably the most satisfac- 

 tory of all aquarium plants. The Wash- 

 ington Grass, Cabomba caroliniana, fre- 

 quently sold by dealers, is not recom- 

 mended. It breaks up easily, and unless 

 the conditions are just right it soon looks 

 shabby. There cannot be too many plants 

 as long as the fishes have room to swim. 

 The surplus oxygen passes off into the 

 atmosphere. 



For the bottom of the aquarium use 

 washed, coarse sand, or sand and gravel. 

 Do not use fine ocean sand. If the plants 

 have roots, spread them well. From one 

 to two inches of sand will be found suffi- 

 cient. 



The next important subject is the num- 

 ber of fishes which may be placed in the 

 aquarium. In spite of advice to the con- 

 trary, the beginner insists on over- 

 crowding, and only learns by repeated 

 failures. As a large fish consumes more 

 oxygen than a small one, there can be 

 no satisfactory rule as to the number of 

 fish used, but there is a very good rule 

 which it will be well to remember — one 

 inch of fish to the gallon of water. This 



is not counting the tail. That is to say, 

 a five-gallon aquarium will properly 

 maintain either one five-inch or five one- 

 inch or ten half -inch fish. 



To calculate the capacity of an aqua- 

 rium in gallons, if it be rectangular, mul- 

 tiply the depth, length and width of the 

 water measurement in inches, and divide 

 the total by 231. 



Avoid globes where possible, but if 

 they must be used, do not fill more than 

 two-thirds full. This gives more air sur- 

 face than when they are filled to the top. 

 The greater the air surface the better, and 

 this applies to any aquarium. Therefore 

 a broad, flat shape is better than a deep, 

 narrow one. Fish undoubtedly do better 

 in rectangular aquaria than in globes, and 

 they can be seen to much better advan- 

 tage. 



An aquarium of less than five-gallons 

 capacity is not very satisfactory for gold- 

 fish. A ten-gallon size is a good one to 

 start with. For many of the tropical 

 fishes it is possible to use quite small 

 aquaria, even down to quart jars. 



Many persons kill their fishes by kind- 

 ness. They overfeed them. Fish in 

 the confinement of an aquarium should 

 not be fed more than will be entirely con- 

 sumed in a few minutes. In moderate 

 and warm weather they may be fed once 

 daily; if the water is cool (50 to 60 deg. 

 F.) every other day is sufficient. If be- 

 low this, once a week. The white rice 

 wafer, the food generally used by the 

 inexperienced, is the least desirable. 

 Nearly all dealers sell a better food in 

 granular form, composed of dried insects, 

 egg and farinaceous substances. 



The best temperature for goldfish is 

 from 65 to 70 degrees F. They can 

 maintain life down to the freezing point, 

 but under artificial conditions necessarily 

 pertaining in an aquarium this is to be 

 avoided. Higher than 80 degrees is also 



