<a href=showthread.php?s=&postid=7443846#post7443846 target=_blank>Originally posted</a> by Acolin
I do not know if the entire volume of the main tank goes out through overflow boxes. There is an entire tank that the public does not see, but which provides the limitless horizon seen from the front side of the main tank. At the top of this second tank is another tidal pool, where water overflows from the main tank. This is where they grow some corals, propagate mangroves and release fish so they can swim out into the main tank only when they are ready to explore further. New fish can stay in the tide pool for days and weeks before venturing out into the larger display.
Much of the water in the tank is pumped through to a row of rotating splash buckets along one edge of the main tank. The buckets fill and dump in a crescendo of flushing power. This action breaks the water surface, retards any build-up of scum or oily surface and mixes the upper waters with those below it.