Photo: Luc Viatour · CC BY-SA 3.0
Saltwater · Intermediate · 125+ gal
Zebrasoma flavescens
Yellow tangs are active Hawaiian surgeonfish that need swimming room, not a nano reef. A home-aquarium minimum is about 125 gallons with length to patrol and rock to graze.
| Water type | Saltwater |
|---|---|
| Care level | Intermediate |
| Minimum tank | 125 gallons |
| Temperament | Active grazer that can be territorial with other tangs, especially in undersized tanks. Usually reef-safe with corals, though it may nip at some fleshy LPS or clams when underfed. |
| Diet | Primarily herbivore. Offer dried nori daily, plus quality marine algae pellets or frozen herbivore preparations. Grazing on established rock is part of the diet. A sterile, new tank is a poor match. |
| Temperature | 72–78 °F |
| pH | 8–8.4 |
| Hardness / salinity | Full-strength marine salinity around 1.024–1.026 specific gravity. Stable alkalinity and regular testing matter more than chasing a GH number. |
Zebrasoma flavescens stays under a foot, but it is built to cruise and graze all day. Retail tanks often show a single yellow tang in 40–75 gallons. That is a juvenile display, not a long-term plan. A hobbyist minimum is about 125 gallons, with as much horizontal swimming length as you can give. Six-foot tanks are a common recommendation.
If your tank is 75 gallons or smaller, choose a different fish. Crowding shows up as aggression, HLLE (head and lateral line erosion), and a fish that never settles.
Yellow tangs graze film algae and nori. In a new, sterile tank they starve slowly even if you toss in pellets. Established live rock, a veggie clip, and a prepared herbivore food are the baseline. Feed nori often rather than one huge sheet once a week.
They have a scalpel-like spine at the tail. Netting and handling can injure the fish or you; use a container when you must move them.
This species has a long history of wild collection in Hawaii, with regulations that have changed over time. Prefer reputable sources, quarantine, and a tank that is actually ready. A yellow tang is not a 'starter marine fish' in the way a captive-bred ocellaris can be.
Ich and other parasites are common on wild-caught surgeonfish. Quarantine with a plan, not hope.
A few listings we would open for this species. Skip anything you already own that still works.
Two Little Fishies SeaVeggies Green, 1 oz
Yellow tangs graze. Dried nori daily is the usual staple, not a flake tossed in once. These green seaweed sheets are the listing we would open for a herbivore.
Clip a piece in the morning and take out what is left after a few hours. Skip this in a sterile new tank with no rock — they still need film algae and a tank that is actually 125 gallons. A veggie clip is cheaper than wasting sheets.
See this listingAqueon Adjustable Pro heater, 300W
A 125-gallon marine tank still needs to sit in the mid-70s F. 300W is the large Pro size. Large tanks in cool rooms often run two heaters rather than one unit at the stop.
Skip a second heater if the room already holds that range. Do not use a 50W kit heater and hope. Confirm placement with a thermometer on the opposite end of the tank.
See this listingInstant Ocean Sea Salt, 50 gallons
Water changes on a 125-gallon are not a cup of salt. A 50-gallon mix is the practical bag size. Mix in a dedicated container and match salinity before it goes in.
Skip mixing in the display. A hydrometer or refractometer is not optional. If you already buy a different marine mix by the bucket, stay on that mix rather than switching brands mid-tank.
See this listingPlan on about 125 gallons with real length as a minimum for one adult. Smaller tanks are a common reason these fish stay stressed and territorial.
Some keepers try it. It is cramped for an active surgeonfish long-term. Choose a different species if that is your footprint.
They graze film and some nuisance algae, but they are not a cure for a dirty tank. Nutrient control still matters.
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