Tank size · Saltwater

What size tank for a Tomini tang? (75 gal minimum)

Tomini tang (Ctenochaetus tominiensis) — adult 6″, medium-bodied, semi-aggressive.

The three sizes — minimum, good, ideal

TierTank sizeWhat it gets you
Absolute minimum75 US galSurvives adult life. No extras — no tankmates beyond the essentials, no aquascape that eats footprint.
Good113 US galRoom for a small community, decor, and parameter buffering. This is where most people should aim.
Ideal188 US galNatural-feeling space. Active swimmers stop pacing, schoolers school freely, aggression drops.

Length matters more than gallons here — a 30-gallon tall (24″ long) and a 30-gallon long (36″ long) hold the same water but support different fish. Tomini tang needs at least 48″ of length.

Parameters at a glance

Temperature
7580 °F
pH
8.18.4
Salinity
3335 ppt
Adult size
6
Body type
medium

Why tank size matters for this species

Tomini tang is an active swimmer. The 48″ minimum length is non-negotiable — they pace the front glass for hours in shorter tanks.

Source for the tank-size minimum

ORA + BRS tang sizing.

Next steps

People also ask

What is the absolute minimum tank size for a Tomini tang?
75 US gallons as an adult, with a minimum footprint of 48″ long. ORA + BRS tang sizing.
Can I keep a Tomini tang in a smaller tank when it's a juvenile?
Briefly, yes — fish stores often sell juveniles that haven't reached adult size yet. But you should plan, buy, and cycle the adult-minimum tank from day one. Upgrading mid-life stresses the fish and is far more expensive than buying the right tank up front.
Can I keep more than one Tomini tang together?
It depends on the species' behaviour (semi-aggressive). Aggressive and semi-aggressive species often need to be kept solo unless the tank is dramatically larger than the minimum. Verify before adding a second.
What temperature and pH does a Tomini tang need?
Temperature 75–80 °F, pH 8.1–8.4, salinity 33–35 ppt.

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