Fast Aquatics

Short answer

Yellow tang (most peaceful, vibrant, tolerates community), kole tang (small, peaceful, exceptional algae grazer), tomini tang (shy but peaceful), or sailfin tang (large but peaceful). Avoid achilles, powder blue, and clown tang in 100 gallons - they need 180+ gallons.

In depth

Tangs (Acanthuridae family) are reef-tank centerpieces but demand swimming space. The 100-gallon mark is roughly the floor for keeping one tang long-term; 125-180 gallons is better for most species; 220+ gallons is required for the demanding ones.

100-gallon tang selection

  • Yellow tang (Zebrasoma flavescens): the standard hobby tang. 5-6" adult, peaceful with most reef inhabitants, exceptional macro-algae grazer, $80-180.
  • Kole tang / Yellow-eye Kole (Ctenochaetus strigosus): 4" adult, the best algae cleanup of any tang, peaceful, $80-150.
  • Tomini tang (Ctenochaetus tominiensis): 4-5" adult, peaceful, similar to kole but slightly smaller adult size, $80-150.
  • Sailfin tang (Zebrasoma desjardinii or veliferum): 8-10" adult, peaceful but large - 100 gallons is the floor for one, 125+ ideal, $120-250.

Avoid in 100 gallons

  • Achilles tang - 180+ gallons, ich-magnet, advanced-only
  • Powder blue tang - 180+ gallons, ich-magnet
  • Naso tang - 220+ gallons, large adult size
  • Clown tang - 220+ gallons, aggressive
  • Two same-species tangs in 100 gallons - even peaceful species fight when confined

More questions

Can I keep two tangs in a 100-gallon?

Generally no. Even peaceful species fight in 100 gallons. The exception: 2 small Ctenochaetus (kole + tomini) sometimes coexist if added simultaneously as juveniles. Plan for fights and remove the loser if needed.

Do I need to feed tangs nori?

Yes, daily. All tangs are primarily herbivorous and need vegetable matter. Nori sheets clipped to the tank, blanched zucchini or spinach, or dedicated algae-based pellet (Algae Wafers, NLS Marine, etc.) are mandatory.