A 12-16 inch fish can live in a 7x2x2 tank just fine. It has enough room to turn around and move, but if it hits 20+ inches you might want to upgrade, but it could workWell yeah tems get huge with their potential to hit 80-100cm in a couple pf years. But to say an kel work fine in an 7x2x2 tank like most people here says is bs to my ears. Kel is a smaller species yeah but still has the potential to reach 50-55cm.