110 



DAVID G. CARGO 



Figure 7. — General view of aquariums. 



water in the tanks. These plugs are 

 threaded into holes tapped into the sides 

 of the standpipes. 



The entire pumping system (fig. 8) is 

 flushed regularly with fresh water held in 

 a 500-gallon tank and coupled into the sys- 

 tem. This water is not heated. Some 

 minor fouling occurs inside the foot valve 

 but has not proved troublesome. This 

 same backwash water is used for priming 

 the pumps when necessary. Naturally, 

 this fresh water is not allowed to enter the 

 supply trough when purging the lines. 

 A feature common to both systems is a 

 strainer which is necessary to avoid the 

 clogging of the intake by jellyfish and 

 ctenophores. After trying several de- 

 signs, we found that a large polyethylene 

 wastebasket pierced by numerous i/4-inch 

 holes and attached to a wooden disk 

 clamped to the intake pipe answers this 

 need nicely. By releasing two bolts (we 



used plastic bolts) , the unit can be disas- 

 sembled and scrubbed. The wooden disk 

 was not painted but is still in good con- 

 dition after 18 months' use. In general, 

 this screen arrangement has proved very 

 efficient and satisfactory. 



EVALUATION AND REMARKS 



The wharf system has provided us with 

 an extremely reliable source of running 

 water for a period of almost 3 years. Ini- 

 tial problems with priming and the 

 strainers w^ere quickly resolved as our 

 familiarity with the equipment increased. 

 The entire system was installed by our 

 maintenance staff at the site; installation 

 required no outside assistance. 



The main research system has given 

 problems which might be considered com- 

 mensurate with the complexity of the sys- 

 tem. Certain mechanical failures have re- 

 sulted, principally from unfamiliarity 



