Depends on the species. A dwarf cuttle (Sepia bandensis) can do ok in a 20 gallon. I've kept one in a smaller space, about 10 gallons while it was a juvenile. They need space, as mentioned above, and don't do well with lots rock work around. For stable params you may need something larger than a 14 gallon. Honestly I kept mine in a tank with 50 gallons of water so I can't say whether it would survive in such a small space as 14 gallons.