AQUARIUM MANAGEMENT 



If one were working on the plan of keeping too many fish and chang- 

 ing the water to keep them alive, then of course the deeper aquarium 

 would last longer without a change, but a real aquarium, reproducing 

 natural conditions, should never need a change. Never? Well, in the 

 famous words from "Pinafore," hardly ever. Once in a great while— 

 somewhere between six months and six years— would be all right. The 

 best of homes, on land or in water, need an occasional housecleaning, but 

 an aquarium under the proper conditions should be able to continue in a 

 healthy condition indefinitely, only adding water to make up for evapora- 

 tion. To prove the correctness of this theory they have in the Aquarium 

 Building at Battery Park in New York City a small aquarium which 

 has not been disturbed for over thirty years ! A thorough cleansing and 

 re-planting once a year should be sufficient for a properly arranged house- 

 hold aquarium. 



Fish Capacity Rule. By this time the patient reader will no doubt 

 like to know how much of this wonderful water-surface a fish needs. 

 Good. Let us put theory into practice. We will first consider the less 

 favorable conditions, which are, highly developed fancy goldfish in a 

 temperature from 78 to 90 degrees Fahrenheit. That is, delicate fish in 

 water containing comparatively little oxygen. Since most of us must 

 keep our fishes in the same container throughout the year, we had best 

 base our calculations on meeting the greatest disadvantages we are likely 

 to encounter, on the principle that a chain is no stronger than its weakest 

 link. A good working rule is Twenty-Four Square Inches of Water 

 Surface to Every Inch of Body Length of Fish. That is to say, an 

 aquarium containing a water surface of 8x12 inches, which makes a 

 square inch area of 96 inches, should, the year round, in the average 

 temperate zone, be able to keep in health either one four-inch, or two 

 two-inch or four one-inch fancy goldfishes. (Mark you, please, the words 

 either and or.) 



The common long-bodied goldfish with single tail is hardier and can 

 do with a little less space. Take people in a closed room. Some of the 

 delicate ones will feel distress before the stronger notice any discomfort. 

 Even common fish, however, should not be given less than eighteen square 

 inches of water surface to the inch of fish body. (These computations all 

 exclude the tails.) It is to be assumed we all know that the square 

 measure is obtained by multiplying the length and breadth together. 



Surface Measure of Circle. The surface measure of cylindrical and 

 globe-shaped aquaria is found by another easy rule. The radius (which 

 is half the diameter) is multiplied by itself. This result is multiplied by 

 3 1/7. For example, a circular surface is 6 inches across. The radius is 

 3 inches. Multiplying this by itself we have 9, and multiplying 9 by 



