Calcium Reactor 624 All cell cast acrylic construction Clear lid to view proper O-ring seal Key hole slot for lid removal Micro ball valve effluent control Pan world pump, bolted to base plate pH probe port in lid pH probe adapter included Auto fill bubble counter 10 x 10 foot print, 29" overall height Holds 16 pounds of media, we recommend large grain schuran type For Large SPS reef aquariums.