How is a 40x20 tank a 120gal? Also, in the video BRS refers to the tank as 4ft, again the tank is 40".
We get this question a lot.
Basically, the tank is a 4ft x 2ft (120gal) system. The actual testing area grid inside the tank is 40" x 20", because we have to make room for the LiCor PAR meter cables as well as the 1/2" glass on all sides.