CLOSED CIRCULATING SEA-WATER SYSTEM 



33 



Figure 4. — One of the three aquarium rooms showing several reinforced-concrete water tables (ap- 

 proximate dimensions 72 by 22 by 4 inches) and a large fiberglass-lined redwood tank (250-gallon 

 capacity). Note banks of stopcocks on wall, also compressed-air line with multiple outlets. 



operation is especially important because 

 hard-rubber and PVC plastic are both 

 brittle and break easily when distorted. 



Among the alternative pump designs 

 which seem attractive are gear pumps with 

 Teflon plastic gears and pump-case linings 

 and Archimedes-screw pumps with plas- 

 tic-coated screws and case lining. 



Second, we would not use redwood as a 

 construction material for any tank in the 

 system. Redwood continues to leak 

 colored materials into the water over long 

 periods — this is still happening in our 

 system after over 3 years of continuous 

 operation. This colored material appears 

 not to be toxic or in any way pharmaco- 

 logically active, but it mars appearance of 



the sea water and hence interferes with 

 observations. Fiberglass-reinforced plas- 

 tic or wooden tanks would seem to be the 

 solution. 



Third, we would not use Transite as ma- 

 terial for return lines. Transite piping is 

 permeable to water and will, therefore, 

 accumulate salt deposits on its outer sur- 

 faces if used to transport sea w^ater for 

 long distances through air spaces. These 

 salt deposits do not seem to weaken the 

 transite itself, but can be the cause of im- 

 portant building deterioration if atmos- 

 pheric water condensation occurs which 

 then results in drip of salt water. The 

 solution is the replacement of all transite 

 with unplasticized PVC pipe. 



