--- type: species title: "Scopas Tang Care Guide: The Algae-Eating Workhorse for Reef Tanks" slug: "scopas-tang" category: "saltwater" scientificName: "Zebrasoma scopas" subcategory: "Tang" lastUpdated: "2026-04-24" readingTime: 11 url: https://www.fishstores.org/species/scopas-tang --- # Scopas Tang Care Guide: The Algae-Eating Workhorse for Reef Tanks *Zebrasoma scopas* Learn how to care for the Scopas Tang (Zebrasoma scopas). Expert tips on tank size, diet, temperament, and why it is the best algae eater for reef tanks. ## Species Overview The Scopas Tang (*Zebrasoma scopas*) is the unsung workhorse of the *Zebrasoma* genus. It carries the same disc-shaped body, sail-like dorsal fin, and razor caudal spine as its more famous cousin the [yellow tang](/guides/yellow-tang-care-guide), but trades the electric color for a subtle two-tone gradient that fades from warm brown at the head to charcoal at the tail. Adults reach about 8 inches and command a fraction of the price of a yellow or [purple tang](/species/purple-tang) — usually $40-80 for a healthy 3-4 inch specimen — which makes them one of the best value algae eaters in the saltwater hobby. Scopas Tangs are the same fish as a yellow tang from a husbandry perspective. The care requirements, feeding schedule, water parameters, aggression patterns, and disease susceptibilities are essentially identical. If you can keep a yellow tang, you can keep a Scopas. If you have been told yellow tangs are too expensive, the Scopas is the obvious substitute — and many hobbyists argue the muted coloration is more elegant once you spend time with the species. | Field | Value | | ----------- | --------------- | | Adult size | 8 in (20 cm) | | Lifespan | 10-20+ years | | Min tank | 100 gallons | | Temperament | Semi-aggressive | | Difficulty | Intermediate | | Diet | Herbivore | > **Sister species to the yellow tang** > > The Scopas Tang and the [yellow tang](/guides/yellow-tang-care-guide) (*Zebrasoma flavescens*) are closely related members of the same genus and share nearly identical care requirements. Tank size, water parameters, feeding schedule, aggression management, and disease prevention all follow the same playbook. If a care article says "yellow tang," assume it applies to the Scopas as well unless explicitly noted. ### The "Brown Tang" Aesthetic: Color Variations and Camouflage The common name "brown tang" undersells this fish. Up close, the Scopas shows a graduated palette running from warm tan or copper around the face and shoulders to deep charcoal-brown along the rear flank and caudal peduncle. Faint horizontal pinstripes run across the body, and the dorsal and anal fin margins carry a subtle pale edge that catches reef lighting. Color intensity shifts with mood. A relaxed, well-fed Scopas in stable water shows the warmest browns and the strongest pinstriping. A stressed fish — newly imported, in a fight with a tank mate, or fighting parasites — washes out to a uniform muddy gray. At night, the fish lightens further and develops a blotchy camouflage pattern as it wedges into a crevice to sleep. None of this is illness; the fish simply wears its mood on its skin. A small percentage of Scopas Tangs are "Koi Scopas" — aberrant individuals with random patches of white, cream, or yellow scattered across the body. These are extremely rare and command prices into the thousands of dollars. Standard wild-type browns are the practical buy. ### Natural Habitat: Indo-Pacific Reefs and Lagoons Scopas Tangs are widely distributed across the Indo-Pacific, ranging from the East African coast through Indonesia and the Philippines out to French Polynesia. They live in coral-rich shallow reefs and lagoons at depths of 3 to 200 feet, with the highest concentrations in clear, oxygen-rich water along outer reef walls. Wide collection range translates to consistent supply and stable pricing — unlike the politically constrained purple tang or the post-ban Hawaiian yellow tang. Wild Scopas spend nearly all daylight hours grazing filamentous and turf algae off rock and coral surfaces. They occur in loose aggregations of 3 to 30 individuals and often join mixed-species feeding groups with other tangs and surgeonfish. Water in their native range averages 75-82 degrees F with strong, consistent flow from open ocean currents. ### Size and Lifespan: What to Expect in Captivity Scopas Tangs reach about 8 inches at full adult size — slightly larger than yellow tangs (7 inches) but smaller than purple tangs (10 inches). Growth in captivity is slow: expect roughly 1 inch per year for the first few years, then tapering off. A juvenile purchased at 3 inches will not hit adult size for at least four years. Lifespan in the wild for *Zebrasoma* species is estimated at 30-40 years based on otolith aging. In captivity, 10-20 years is realistic with proper care, and well-maintained Scopas Tangs have been documented living past 25 years in stable home reef systems. This is a fish you commit to for a long time. ## Water Parameters & Tank Requirements Scopas Tangs are forgiving by tang standards but still demand a properly sized, well-cycled, oxygen-rich tank. The numbers below are minimum standards for long-term health, not aspirational targets. ### Minimum Tank Size: Why 100 Gallons is the Real Answer You will see "75 gallons" listed as a minimum in older sources and big-box store care cards. Ignore it. The practical minimum for a Scopas Tang is 100 gallons with a footprint of at least 5 feet long, and 125-150 gallons gives you a meaningful comfort margin for an adult fish. A standard 100-gallon tank (60" x 18" x 20") provides the horizontal swimming length the species needs. The reason is behavioral, not chemical. Scopas Tangs are open-water grazers that swim continuously across reef faces in the wild. In a too-small tank, they pace the same path back and forth, stress-clamp their fins, and develop HLLE within months. Tank size directly drives long-term tang health more than almost any other variable. Cube tanks are a poor fit. A 90-gallon cube has the same gallonage as a 75-long but less swimming distance. For any *Zebrasoma* species, choose footprint over height every time. ### Flow and Oxygenation: Replicating High-Energy Reef Zones Aim for total tank turnover of 20-40x per hour through a combination of return pump flow and powerheads. Scopas Tangs come from current-swept reef faces and physically swim against flow as part of their natural behavior. A tank with weak, laminar flow leaves them listless. Oxygenation matters as much as raw flow rate. Surface agitation from return pumps, wave makers, or a protein skimmer's air intake is essential. If the surface is glassy and still, dissolved oxygen will be marginal during nighttime when corals respire and consume O2. A protein skimmer is non-negotiable on any tang tank — it both oxygenates the water and removes dissolved organics that fuel disease. Position powerheads to create chaotic, multidirectional flow rather than a single laminar stream. Tangs use varied flow zones to choose where they want to be, which reduces stress. ### Specific Parameters: Temp, pH, Salinity, and Nitrate ### Scopas Tang Water Parameters | Parameter | Target | Notes | | ---------------- | ----------------- | ------------------------------------------------------------- | | Temperature | 75-80°F (24-27°C) | Stability matters more than the exact number | | Salinity / SG | 1.023-1.025 | Use a refractometer, not a swing-arm hydrometer | | pH | 8.1-8.4 | Standard reef range | | dKH (Alkalinity) | 8-12 dKH | Stability is more important than absolute number | | Calcium | 400-450 ppm | Required for coral growth in mixed reef tanks | | Magnesium | 1280-1350 ppm | Maintains proper Ca/Alk balance | | Ammonia | 0 ppm | Any detectable level is toxic | | Nitrite | 0 ppm | Must be zero before adding any fish | | Nitrate | \<10 ppm | Tangs are nitrate-sensitive; high nitrate contributes to HLLE | | Phosphate | \<0.05 ppm | High phosphate fuels nuisance algae and degrades coral health | The most underrated parameter for tang health is nitrate. Plenty of reef keepers tolerate 20-40 ppm nitrate because their corals seem fine. Tangs do not tolerate this for long. Keep nitrate under 10 ppm through weekly 10-15% water changes, a properly tuned protein skimmer, and a refugium with chaeto or other macroalgae. > **Ich magnet — sensitive to parameter swings** > > Tangs are notorious "ich magnets" because their thin scales and high stress sensitivity make them the first fish to break out with white spots after any disturbance. A 2 degree F overnight temperature drop, a salinity swing from a sloppy water change, or a pH crash from an overdosed alkalinity supplement is enough to trigger an outbreak in a Scopas Tang. Invest in a quality temperature controller, calibrate your refractometer monthly, and dose two-part alkalinity slowly. Stability prevents disease far more reliably than treating it after the fact. For a deeper dive into reef chemistry fundamentals, see our [saltwater aquarium guide](/guides/saltwater-aquarium). ## Diet & Feeding Scopas Tangs are obligate herbivores. Their entire digestive tract is built to process algae, and feeding them like an omnivore is the fastest path to organ damage and HLLE. ### The Importance of Marine-Based Macroalgae (Nori) Nori (dried sheets of *Porphyra*) should be the foundation of the diet. Clip a fresh sheet to the tank using a veggie clip every day, and let the tang graze continuously between meals. Two-thirds of a sheet per day is appropriate for a 5-inch fish; an adult will eat a full sheet daily. Buy unseasoned, additive-free nori from an aquarium supplier or the Asian foods aisle of a grocery store. Sushi nori with added salt or seasonings is not appropriate. Rotate between green, red, and purple nori varieties for a broader micronutrient profile. Live or dried macroalgae like *Gracilaria* (red ogo) and *Ulva* (sea lettuce) is even better when you can source it. Many reef stores sell live macroalgae for refugiums, and a portion can be fed to the display tank. Tangs that eat fresh macroalgae instead of dried nori show noticeably better body condition and color saturation. ### Supplementing with Frozen Mysis and Spirulina While Scopas Tangs are herbivores, they will eagerly eat frozen mysis shrimp and other meaty foods. Feed these as occasional treats — no more than 2-3 times per week, and never as the bulk of the diet. A tang fed mostly mysis shrimp develops fatty liver and digestive problems over the long term. The right ratio is roughly 70% algae-based foods (nori, dried/live macroalgae, herbivore pellets like New Life Spectrum AlgaeMax), 20% mixed frozen prep (Rod's Food Herbivore Blend, Larry's Reef Frenzy Vegetarian), and 10% meaty treats. Feed two to three times per day in small amounts rather than one large daily meal. Spirulina-based pellets and flakes are excellent supplementary foods. They deliver beta-carotene and amino acids that intensify body coloration over time. New Life Spectrum, Ocean Nutrition Formula Two, and TDO chroma-boost are all reliable picks. ### Preventing Lateral Line Erosion (HLLE) Through Nutrition HLLE is the chronic killer of long-term tang health. It develops slowly over months and erodes facial tissue and lateral line organs. The most consistent preventable contributor is dietary deficiency in vitamins and HUFAs (highly unsaturated fatty acids). Soak nori and frozen foods in Selcon or VitaChem two to three times per week before feeding. These supplements deliver vitamins A, B, C, D3, and E along with HUFAs that herbivorous tangs cannot synthesize on their own. The improvement in color and energy is visible within a few weeks of consistent supplementation. Vitamin C is particularly important. Wild Scopas Tangs get vitamin C from the algae they graze on; captive tangs eating only dried nori may not get enough. A weekly drop of liquid vitamin C onto food is cheap insurance against HLLE. > **Don't feed your tang like a clownfish** > > The most common feeding mistake is treating tangs like the rest of the tank — pellet in the morning, frozen mysis at night, done. Tangs are grazers. Their guts are built for continuous, low-volume intake of fibrous algae. Without a constant nori clip in the tank, they pace, lose color, and become aggressive toward tank mates because they are physiologically hungry between scheduled feedings. ## Tank Mates & Compatibility Scopas Tangs are semi-aggressive and become more territorial as they mature. Stocking order, tank size, and species selection all matter — and the rules here mirror what works for any *Zebrasoma* species. ### Reef Safety: Are They Coral-Safe? Scopas Tangs are 100% reef safe. They will not nip hard corals, soft corals, anemones, clams, snails, hermit crabs, shrimp, or any other invertebrates. They are one of the best natural algae-control fish available and many reefers consider them essential for managing nuisance hair algae and bryopsis. The only caveat: a starving tang may sample coral polyps or zoanthids if there is no algae available. This is not normal behavior and indicates underfeeding rather than a true reef incompatibility. Keep the nori clip stocked and this will not happen. ### Managing *Zebrasoma* Aggression: The Same Issues as Yellow and Purple Tangs > **Same aggression issues as yellow and purple tangs** > > Scopas Tangs share the *Zebrasoma* body shape, feeding niche, and territorial instincts of yellow and purple tangs. That means the same aggression rules apply: do not house a Scopas with a [yellow tang](/guides/yellow-tang-care-guide) or [purple tang](/species/purple-tang) in tanks under 180 gallons, and never assume the muted brown coloration somehow means a peaceful temperament. A Scopas will harass a same-genus tank mate just as relentlessly as the yellow tang it most resembles. The most reliable rule for stocking tangs: add them last, or near last. A Scopas introduced to an established tank where it is the new arrival is far less likely to bully existing fish than one added first that views every new addition as an intruder. If you must introduce a Scopas to an existing aggressive population, use a 7-day acclimation box (a clear plastic container with holes drilled for water flow, suspended inside the display tank). The new fish acclimates to its surroundings while existing fish lose interest. Release after a week of normal behavior on both sides. Aggression escalates with maturity. A 3-inch juvenile Scopas may coexist peacefully for a year, then suddenly start attacking same-genus tank mates as it crosses the 5-inch threshold. ### Ideal Community Mates: Blennies, Wrasses, and Large Inverts Good tank mates include clownfish, royal grammas, firefish, gobies, fairy and flasher wrasses, cardinalfish, anthias, and most peaceful reef fish. Strong pairings for a Scopas community tank: | Tank Mate | Why It Works | Notes | | ----------------------------------------------------------------- | --------------------------------------------- | ------------------------------------------ | | Clownfish (Amphiprion spp.) | Different zone — clowns stay near host | Classic reef pairing | | Wrasses (fairy, flasher, six-line) | Mid-water swimmers, different niche | Avoid large aggressive wrasses | | Gobies and blennies | Bottom-dwellers, stay out of the tang's way | Excellent cleanup companions | | Royal gramma | Cave-dwelling and peaceful | Holds territory in rocks, no conflict | | Anthias | Schooling fish in upper water column | Need frequent feeding like tangs | | \[Tomini Tang]\(/guides/tomini-tang-care-guide) (different genus) | Different body shape, different feeding niche | Better tang pairing than another Zebrasoma | | \[Blue Hippo Tang]\(/species/blue-hippo-tang) | Different body shape, different genus | Workable in 180+ gallon tanks | *Compatible tank mates for a Scopas Tang in a 100+ gallon reef* > **Single specimen — extreme conspecific aggression** > > Two Scopas Tangs in the same tank is a near-guaranteed fight to the death unless the tank is enormous (300+ gallons) and the fish are introduced simultaneously as small juveniles. Conspecific aggression in *Zebrasoma scopas* is among the most extreme in the genus — the dominant fish will chase, slash with its caudal spine, and prevent the subordinate from eating until it stops trying. Plan for a single Scopas Tang per system. If you want a multi-tang display, choose different genera (a Scopas plus a [tomini tang](/guides/tomini-tang-care-guide) or a [blue hippo tang](/species/blue-hippo-tang)) rather than two browns. Avoid pairing Scopas Tangs with very small or shy fish that will be intimidated by the tang's bold personality, and avoid triggers and large aggressive angelfish that will outcompete them for food. ## Common Health Issues Scopas Tangs are prone to the same three health problems as every other tang in the hobby. All three are preventable with proper care. ### Marine Ich and Velvet: Why Quarantine is Mandatory Tangs are the canary in the coal mine for parasites. Marine ich (*Cryptocaryon irritans*) appears as scattered white grains of salt across the body and fins. Marine velvet (*Amyloodinium ocellatum*) is the more dangerous cousin — it presents as a fine gold-dust film and kills within days if untreated. Treatment for both requires a separate quarantine tank with copper-based medication (Copper Power, Cupramine) at therapeutic levels (0.5 ppm) for 30 days. Never medicate a display reef — copper kills invertebrates and binds permanently to live rock and substrate. A 4-6 week quarantine in a separate tank is the standard for any wild-caught tang. Use a 40-gallon breeder as a minimum quarantine size — anything smaller stresses the fish further. Run the QT with a sponge filter, a heater, PVC hiding spots, and bare-bottom substrate. Treat prophylactically with copper for 30 days, then observe for an additional 2 weeks at therapeutic-free conditions before transferring to display. For full step-by-step acclimation guidance, see our [how to acclimate fish guide](/guides/how-to-acclimate-fish). ### Treating Skin Flukes and Parasites Scopas Tangs occasionally arrive with monogenean skin flukes — small flatworm parasites that attach to the skin and gills and cause flashing, scratching, and labored breathing. Flukes do not respond to copper. Treat with a praziquantel bath in quarantine (Prazipro at the labeled dose, repeat after 5-7 days to catch newly hatched eggs). Other parasites occasionally seen on imported tangs include intestinal worms (treat with metronidazole-laced food) and Brooklynella (a flagellated protozoan, treat with formalin in quarantine). All of these are easier to address in a 30-gallon quarantine tank than in a 200-gallon reef display. ### HLLE — The Slow-Motion Killer HLLE causes pitting and erosion around the head and lateral line, often starting as small pinholes near the eyes and progressing to large, cratered patches. It is disfiguring but treatable if caught early. Causes include nutritional deficiency (lack of HUFAs and vitamin C), poor water quality (high nitrate, high phosphate, low dissolved oxygen), activated carbon dust, and stray voltage from damaged equipment. Early-stage HLLE often reverses completely within 2-3 months once you correct diet, water quality, and add a grounding probe. A Scopas Tang that consistently receives nori, macroalgae, vitamin-soaked food, and clean water will almost never develop HLLE. ## Where to Buy & What to Look For Buying a healthy Scopas Tang is half the battle. A wasted, parasite-ridden specimen from a sketchy importer dies regardless of how good your tank is. ### Assessing Body Thickness and "Pinched" Bellies Look at the fish from above (top-down view in the dealer's tank if possible). A healthy Scopas has a rounded, full body with no concavity behind the head or along the belly. A "pinched" appearance — where the body narrows just behind the gill plate or the belly visibly hollows — indicates internal parasites or chronic underfeeding during shipping. A pinched tang can sometimes be rehabilitated with aggressive feeding and metronidazole-laced food, but the survival rate is poor. Walk away unless the price is heavily discounted and you have rehab experience. The dorsal fin tells you a lot. A confident, healthy tang holds its dorsal fin erect or at least partially raised. A clamped, folded dorsal indicates stress or illness. ### Ask the LFS to Feed the Fish in Front of You Ask the store to drop a piece of nori in the tank while you watch. A healthy Scopas Tang should approach within 30 seconds and start nipping aggressively. A tang that ignores food, mouths it tentatively, or refuses to leave the rockwork is not a buy — period. This single behavioral test screens out more bad fish than any visual inspection of color or fin condition. Better yet, ask how long the fish has been in the store's holding system. A Scopas that has been in the dealer's tanks for 7-10 days has survived the most dangerous post-shipping window and is statistically more likely to thrive long-term. Reputable dealers volunteer this information; ones that get evasive about arrival dates are the ones to skip. > **Buy a Scopas Tang in person, not sight-unseen** > > Scopas Tangs are widely available and reasonably priced ($40-80 for a 3-4 inch specimen at a quality LFS), so there is no reason to gamble on a sight-unseen online purchase. Inspect the body for ich and velvet under good light, watch the fish eat nori, and confirm the dorsal fin is held erect. The premium for buying at a quality local fish store is worth every dollar compared to the cost of replacing a dead one. ### Scopas Tang Local Fish Store Health Check - [ ] Body is full and rounded when viewed from above — no pinching behind the head or along the belly - [ ] Color is a graduated brown to charcoal — washed-out muddy gray indicates stress - [ ] Dorsal fin is erect or partially raised, not clamped flat against the body - [ ] Active grazing on nori or algae when offered — fish approaches food within 30 seconds - [ ] No visible white spots (ich), gold dust (velvet), or cloudiness on body, fins, or eyes - [ ] Ask how long the fish has been in the store — 7-10 days minimum is the safe purchase window ### Identifying Rare "Koi" or Aberrant Color Morphs A small percentage of Scopas Tangs come out of the wild with random patches of white, cream, or yellow scattered across the brown base — these are "Koi Scopas" and command premium prices into the thousands of dollars. They are extremely rare and almost never appear in standard LFS shipments. If you see one labeled as a Koi Scopas at a normal price, inspect carefully — partial color shifts can also be caused by HLLE scarring or stress lightening rather than true aberrant pigmentation. For a broader overview of selecting healthy marine fish, see our [saltwater fish guide](/guides/saltwater-fish). ## Quick Reference - **Tank size:** 100 gallons minimum, 125+ gallons recommended for adults; 5-6 foot footprint preferred - **Temperature:** 75-80°F (24-27°C) - **Salinity:** 1.023-1.025 SG - **pH:** 8.1-8.4 - **dKH:** 8-12 - **Nitrate:** Under 10 ppm — tangs are nitrate-sensitive - **Diet:** Herbivore — daily nori, frozen herbivore prep, occasional mysis treats - **Supplements:** Soak food in Selcon or VitaChem 2-3x per week to prevent HLLE - **Flow:** 20-40x tank volume per hour, multidirectional, well-oxygenated - **Tank mates:** Clownfish, gobies, wrasses, anthias, royal grammas; avoid other *Zebrasoma* in tanks under 180 gallons - **Reef safe:** Yes, 100% - **Aggression:** Semi-aggressive; single specimen per tank, add last to minimize territoriality - **Common diseases:** Marine ich, velvet, HLLE, skin flukes - **Quarantine:** 4-6 weeks mandatory in a separate copper-treated QT tank - **Lifespan:** 10-20+ years with good care - **Difficulty:** Intermediate - **Price:** $40-80 for a healthy 3-4 inch specimen ## Frequently Asked Questions ### Are Scopas Tangs reef safe? Yes, they are considered 100% reef safe. They spend their days grazing on nuisance algae and will not bother stony corals or softies, though they may occasionally nip at a coral if they are underfed. ### How big do Scopas Tangs get? In a home aquarium, they typically reach 6 to 8 inches. Because they are active swimmers, they require at least a 5-foot long tank (100 gallons minimum) to thrive. ### Are Scopas Tangs aggressive? They are semi-aggressive, particularly toward other Zebrasoma species (like Yellow or Sailfin Tangs). It is best to add them last to a community tank or use an isolation box to mitigate territorial disputes. ### What do Scopas Tangs eat? They are primary herbivores. While they eat flake and frozen food, their diet must be anchored by high-quality seaweed (Nori) and algae-based pellets to maintain their immune system. ### Why is my Scopas Tang changing color? Scopas Tangs can change intensity based on stress or nighttime camouflage. However, they are also known for aberrant color shifts; some rare individuals may develop white or yellow patches, known as Koi Scopas. --- *Source: [FishStores.org](https://www.fishstores.org/species/scopas-tang)* *Last updated: April 24, 2026*