MARINE AQUARIA 



More water than is required to fill the aquarium should be prepared so 

 that a part may be kept in reserve, which, in a cool place, will not deter- 

 iorate but improve in quality and in fitness for use in case of necessity, 

 which may happen to the novice. 



Hydrometer. A hydrometer or specific gravity bulb is not abso- 

 lutely necessary but is useful. Seawater has a specific gravity of 1.023 ^o 

 1.03 1, which means that a volume equal to one cubic centimeter is approxi- 

 mately .027 grams heavier than the same volume of freshwater of the 

 same temperature, customarily taken at io°C. or 50°F. Should the 

 hydrometer sink below this point, then the water is not sufficiently saline, 

 or should it rise above,it is too concentrated. Having established the degree 

 of salinity of the water when the aquarium has been filled, its maintenance 

 is simple; evaporation to produce concentration is only the wellwater, 

 which may be filled in, or should changes occur to affect the degree of 

 salinity, a part of the water may be siphoned and some of the reserve 

 water added, to again establish the correct balance. This very rarely or 

 never occurs. 



Before the living inmates are introduced, the aeration should be 

 operated for some time, that the water will be charged with air, to revive 

 the animals after their exhausting journey or from other disturbances 

 which may affect their survival. 



Temperature. With proper aeration the temperature of the water 

 does not seriously affect the inmates. Those of the household, of 70°F. 

 to 80° F. in the summer, are not injurious, if the air supply is sufficient; 

 for which reason the aeration should be more considerable in warm than 

 in cool weather. The activity of the animals also increases with the tem- 

 perature, whereby they liberate more carbonic acid gas and require a cor- 

 responding increase of oxygen for their comfort. 



Marine Aquarium Plants. The growth of plants in the marine 

 aquarium for other than ornamental purposes has never been satisfactorily 

 accomplished. No dependence can be placed on them to serve as oxygen- 

 ators; for, though they are of most exquisite and delicate forms and 

 beautiful colors, they are all of the lower order of cryptogamous plants 

 which rank as very indifferent generators of oxygen. 



Marine Flora. These marine cryptogams or algals are all non- 

 flowering, cellular plants, which may be classed by their colors, as this 

 very nearly corresponds with the botanist's classification based on their 

 methods of reproduction. The lowest and simplest forms, Chlorospermese, 

 are bright or grass-green in color, the next higher, MelanospermeEC, olive- 

 colored, and the highest forms, Rhodospermeae, are red in color. All have 

 a wide range of distribution in America and Europe, and consist of arctic, 



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