274 



tX. S. BUREAU OF FISHERIES 



from the sea beinof clone at times of highest tides. When renewals 

 can be made with little expense the practice is desirable, of course. 



Analysis of sea icuter at the New York Aquarium reservoir, installed in 1908, 

 tcith addition)^ made later. Date of collection May 12, 1927: sample number 



187857 



[Analysis by bureau of water supply, city of New York, Dr. Frank E. Hale, director of laboratories] 



Analyses 



1 



7 



2 1 V 



Physical examination: 



Turbidity (p. p. m. silicat -._ 



Color (p. p. m. platinum) 



Odor 



Chemical examination: 



Albuminoid ammonia (p. p. m. nitrogen) 



Free ammonia (p. p. m. nitrogen) 



Nitrite (p. p. m. nitrogen) 



Nitrate (p. p. m. nitrogen) 



Total solids (p. p. m.) 



Chlorine (p. p. m.) 



Hardness (p. p. m. calcium carbonate)... 

 Alkalinity (p. p. m. calcium carbonate). _ 

 Iron (p. p. m.) 



Sea water • 



40,000 

 18,500 

 6,000 



.075 

 .075 

 .005 

 .25 



.30 



1 Typical composite of deep-sea water. 2 The vindicates vegetable. 



DISTRIBUTING TANKS 



The water supply of an aquarium flows to the exhibition tanks 

 from large distributing tanks situated at a higher level. If there are 

 both salt and fresh water supplies, there will be two sets of dis- 

 tributing tanks. It is necessary to have two or more such tanks 

 for each supply if different water temperatures are required. One 

 of the salt-water tanks will be fitted with a steam coil to provide a 

 temperature suitable for tropical exhibits. One of the fresh-water 

 tanks will be used for the distribution of refrigerated water. 



Two of the three fresh-water distributing tanks in the New York 

 Aquarium are equipped as giuvity filters to insure as great clarity 

 of water as possible. This in no way les.sens their serviceability as 

 distributing tanks. The filtering equipment in the bottom of these 

 two tanks is similar to that used for sea water, described elsewhere. 

 The three fresh-water distributing tanks are cylindrical and made 

 of wood, averaging 8 feet in diameter by 5 in depth. The four tanks 

 used for sea water are of similar construction, two of them being 

 somewhat larger. The proper water levels in the distributing tanks 

 are maintained automatically by float-controlled valves. 



AERATION 



Aerating the water as it is distributed to each exhibition tank has 

 been found helpful. It permits some reduction of flow, which is 

 worth while economically if circulating pumps have to be driven 

 at full capacity. It helps in clarification, and if the aeration is 

 managed properly, it makes the inflowing current, charged with fine 

 air particles, visible. A supply pipe fitted for aeration is extended 

 to the bottom of the tank, whence the air-charged water rises like 

 a fountain, adding an element of liveliness to the picture, otherwise 



