The shallow water tank is on my welded 20 gallon long rack which holds 6x 20s per shelf for 3x shelves holding 18 tanks with a 150 gallon tank on the top.
On the right is the full depth stand pipe with perforated pipe covered in fine mesh. This set up can allow newly hatched goldfish to be raised on recirculating water without them going down the drain. On the left is the shallow water BBR drain which is installed vertically and is simply perforated pipe and a cap.
Here it is just after installation. Each tank has air, recirc water and draining to central system. In this picture it is still missing a few tanks on the bottom and has the old 29 gallons on top which have since been replace with a 150 acrylic tank on top.
