In stocking;- an aquarinni it is most essential that tlie number of fisli introduced be no greater tlian 

 tlie available supply of oxygen will easily maintain. Small fish aie preferaljle to large ones, because 

 they recjuire less attention and more can be accommodated ; and those 2 in 5 inches long are the most 

 satisfactory, h^or fish 3 inches long or less, there shouhl be two-thirds of a gallon or one gallon of 

 water apiece, while for specimens 4 to 5 inches long at least two gallons of water apiece sliould be 

 ])r()vided, in a balanced aquarium. 



To make an aquarium Ijalanced or self-sustaining, it is necessary to intrnduce plants that are 

 adapted to such an environment. There are many kinds of non-flowing plants that comliine utility with 

 beauty, and in almost every communit\- water plants suitable for introduction into aquaria may be 

 found in ponds, lakes, and streams. Anmng the most desirable are milfoil [MynnphyUiiiu ). liDrnworl 

 (Ceratof^hvlliim), eel-grass { rallisiieria ), fanwort {Ciibonibn ). pmid weed ( Polaiiioijctoii ), swamji 

 loosestrife (Liidwigia), and water weed (Aiiacliaris). 



Two or three kinds of the foregoing are sufficient for one aquarium, at one time, and the species 

 mav be \'aried at fre(|uent intervals if desirable. A good comljination is a floating plant with a rooted 

 line. In a large aijuarium some of the flowering plants — like the water hyacinth (Piaropiis) or the 

 arrowhead { Sac/itfaria) — may be inserted in limited numbers. \"arious filamentous alg;e are likely to 

 be introduced incidentall}' with the other ])Ianls, and unicellular alg;e are certain to occur and at times 

 may multiply to sucli an extent as to make the water green and turliid, thus obscuring the fish. Alg;c 

 frequently cc:)at the glass sides of aquaria, and ma\- necessitate the cleaning, particularly of the front, 

 in order to permit a proper view of the interior. .V superalnmdant growth of plants will require 

 removal, of the suiplus or a diminution in the amount of light. 



Bottoms of house a(|uaria may be covered lo the depth of 1'^ to 2 inches with gra\'el or clean 



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