I just recently had a calcium reactor built for 2000 gal.+ tank because I was unable to maintain calcium/alkalinity levels with 2 large Korralin reactors. My tank is 700 gal total water volume. Frank at Reef Concepts built it for me and this thing is AWESOME! The design is exceptional, craftsmanship is excellent, and performance is outstanding! I also have a large Aerofoamer with his new "cleanable" beckett injector. Can't say enough about his products and experience. Thanks Frank! Russ