Lightly Medicated | Yellow Tang

What “Lightly Medicated” means

This is the same animal as our non-quarantined listing, held briefly in our systems and given one short prophylactic course — a light treatment for ich and for internal and external worms — then observed eating in front of us before it goes home.

A light course knocks the parasite load down. It does not guarantee full removal, and we will not pretend otherwise. Ich is only killed in its free-swimming stage, and a short treatment window can miss cysts entirely; worm burdens can survive a single dose. Clearing an animal takes the full quarantine window — 40 to 90 days depending on the species — which is exactly what the Quarantined listing is for. This tier buys you a lower parasite load and a fish we have watched eat, not a cleared animal.

We condition the fish on our end. Every animal we medicate is brought back onto prepared food on our own systems and is eating before it leaves — in practice it is rare for a lightly medicated fish to ship out and arrive sick. Do the same at your end: get it eating in your aquarium before you count it settled.

When it ships

Plan on 5–7 days on our systems for the treatment course, and it does not leave until it is eating. If the animal is not already in our systems we source it first — allow up to two weeks for it to reach us before that clock starts. From the day you order, plan on roughly three weeks in total.

The guarantees

• Shipped orders: 24-hour live guarantee from confirmed delivery.
• In-store pickup: 7-day live guarantee — bring a water sample from your aquarium so we can test it before your livestock goes home with you.

Want the full program — treated, observed, confirmed eating, and covered for 28 days on pickup? That is the Quarantined listing. Run your own quarantine and just want the fish this week? The non-quarantined listing is cheaper still. The whole ladder is explained in Quarantined vs Non-Quarantined.

Yellow Tangs (Zebrasoma flavescens) are about as recognizable as reef fish get — solid, saturated yellow from nose to tail with essentially nothing else competing visually, which is exactly why they’ve been a mainstay of the marine hobby for decades. They have a party trick most keepers never catch: at night, the color drains to a blotchy white-and-red sleep pattern that would fool anyone who didn’t know what they were looking at into thinking it’s a different fish entirely. The pattern reverses fully by morning.

Originally from the Hawaiian Islands (Hawaii and Johnston Atoll are the primary collection range, though they extend across parts of the Pacific), Yellow Tangs are genuinely hardy once established — more so than many other surgeonfish — and they’re constantly active, working over live rock and refugium-grown macroalgae as their primary food source. That grazing behavior is the point: a healthy, well-fed Yellow Tang is one of the better natural algae management tools available in a reef system.

Like every surgeonfish, they carry a sharp, retractable scalpel blade on either side of the caudal peduncle — primarily defensive, but capable of causing a real cut during rough handling. They’re territorial toward other tangs, particularly other yellow tangs in small tanks, so introduce them carefully or provide adequate space for territories to form without constant conflict.

Scientific name: Zebrasoma flavescens
Origin: Hawaiian Islands and Johnston Atoll — shallow-to-mid-depth reef zones dominated by coral rubble and algae growth
Water parameters: Temp 74–82°F · Salinity 1.023–1.026 · pH 8.1–8.4
Tank requirements: 100 gal minimum; needs open swimming space; rock for algae grazing
Diet: Herbivore — nori seaweed, algae-based pellets, live macroalgae; supplement with meaty foods occasionally
Compatibility: Semi-aggressive; territorial toward same genus; reef safe with corals and most invertebrates
Husbandry note: Yellow Tangs held in bare hospital or quarantine tanks deteriorate quickly without a grazing surface. Attach a clip of nori to the tank wall during QT — it reduces stress and keeps the fish eating while you treat.