They may not reach 12 inches, BUT, if I were you, I'd put Nosferatu species in that tank. Breed Yellow Labridens, or Bartoni, or Pantostictus. Pick a species and breed 'em. If you did Labridens from a reputable online source, you could do well selling Labridens. Post lots of pics, if they look good as adults, you'd sell every fry.