I NEED another display tank and have an idea how to convert my current sump (above the tank) into another display while keeping it a sump. . . Currently sump is 10 gallon tank (fills to about 7 gallons), but the rack it is on was made for a 20gallon long. I plan to get a 20L and convert 1/3 of the tank into an all in one/sump (about 6 gallons) and use the other 2/3 as a display. . . HAHAHA