One thing to be aware of, is clown loaches grow EXTREMELY slow. It could take them (approximately) 8+ years to hit 8-9". So I do agree that a 6'x2' would be a good minimum tank size in the long run, it will take a long time before they need a tank that big if you're growing them from babies.
Sent from my SCH-I535 using MonsterAquariaNetwork App