Green Severum Care Guide: The 'Poor Man's Discus' for Your Aquarium

Species Overview#

The Green Severum (Heros efasciatus) is the wild-type form of one of the most beloved large South American cichlids in the hobby. Often nicknamed the "poor man's discus" for its tall, compressed disc shape and calm demeanor, the Green Severum carries the dusky olive coloration and faint vertical banding that decades of selective breeding stripped out of its more famous cousin, the Gold Severum. For keepers who want the natural look — a fish that wears the colors evolution gave it instead of a captive-bred color morph — the Green is the original article.

In the wild, Heros efasciatus drifts through the slow tributaries and flooded forests of the Amazon basin, picking at fallen fruit, seeds, and the occasional invertebrate. That foraging lifestyle bred a thoughtful, deliberate fish that holds its territory but does not pick fights. Among large cichlids, the Severum is the rare option that actually earns the "community-safe" tag — provided its tankmates are the right size and disposition.

Adult size

8 in (20 cm)

Lifespan

10+ years

Min tank

75 gallons

Temperament

Peaceful (for a cichlid)

Difficulty

Intermediate

Diet

Omnivore (heavy plant matter)

Origin: The Amazon Basin and Flooded Forests#

Wild Green Severums inhabit the slow, tannin-stained waters of the Amazon River and its major tributaries, with a stronghold in the seasonally flooded igapo forests of central Amazonia. During the wet season, the water rises into the surrounding forest, and the Severums move into the flooded leaf litter to forage on fruit, seeds, insects, and small crustaceans. Water there is soft, acidic, and warm — pH often dropping below 6.0, hardness near zero, and temperature in the high 70s to low 80s.

Replicating that biotope at home is not strictly required for captive specimens (most are tank-bred), but the closer you get to those conditions, the deeper the green pigmentation and the more reliably the fish will spawn.

Physical Traits: The Compressed Disc Shape#

Green Severums are deep-bodied and laterally compressed — taller than they are wide, with a body shape that recalls a discus or a large angelfish more than a typical cichlid. The base color is a soft olive-green that warms to bronze under good lighting, broken by 7 to 9 faint vertical bars that fade in and out depending on mood. A heavier, darker terminal bar runs through the rear half of the body and is the most reliable identification mark on younger fish.

Mature males develop more pointed dorsal and anal fins, and their faces pick up broken patterns of dark spotting and lines around the eyes and gills. Females stay slightly smaller and rounder with cleaner facial markings.

Lifespan: 10+ Years with Proper Husbandry#

A well-kept Green Severum routinely lives 10 years or more, with documented cases pushing 15 in pristine conditions. That is a long-term commitment — a juvenile bought at the local fish store this spring is a fish you will be looking at well into the next decade.

Water Parameters & Tank Requirements#

Severums tolerate a wide pH range, but they reward keepers who match their natural Amazon habitat with deeper color, faster growth, and more reliable spawning behavior.

Minimum Tank Size: Why 75 Gallons Is the Baseline#

A single Green Severum can technically survive in a 55-gallon tank, but 75 gallons should be the practical floor for any keeper planning to grow the fish to full adult size. For a bonded pair or a community setup with other large fish, step up to a 90 or 125-gallon. Length and width matter more than tall, narrow show tanks — Severums are deep-bodied and need horizontal turning room, not vertical climb space. A 75-gallon tank measuring 48 inches long by 18 inches wide gives them a usable footprint; an 18-inch tall show tank with the same gallonage does not. Our aquarium dimensions guide walks through the footprint and water-volume math worth checking before you commit to a final tank.

Aquascape with smooth driftwood, a few large rounded stones, and a fine sand or smooth gravel substrate. Sharp decor is a bad match for cichlids that root around in the substrate and bump into hardscape during territorial display.

Ideal Parameters: Soft, Slightly Acidic Water (pH 6.0-7.5; Temp 75-84°F)#

Hit the marks of the species' native Amazon biotope where you can:

• pH: 6.0 to 7.5 (they tolerate slightly higher, but show best color in soft, acidic water)
• Temperature: 75 to 84 degrees F (78 to 80 is the sweet spot)
• Hardness: 4 to 12 dGH (soft to moderately soft)

Driftwood, Indian almond leaves, and a small bag of peat moss in the filter will leach tannins that drop the pH naturally and tint the water the light tea color these fish evolved under. The amber tint is not just cosmetic — it tends to bring out the deeper olive-greens and warmer body tones that cooler, harder water washes out.

Filtration and Flow: Managing the Bio-load of a 10-Inch Fish#

Green Severums eat heavily, defecate accordingly, and stir up the substrate while foraging. Plan for filtration rated at twice your tank volume per hour at minimum. A canister filter sized for a tank one step up from yours (e.g., a 90-gallon-rated canister on a 75-gallon tank) is the standard recommendation. Hang-on-back units can supplement but rarely keep up alone on tanks over 55 gallons stocked with cichlids this size.

Weekly 25 to 30 percent water changes are non-negotiable. Nitrate creep is the slow killer in cichlid tanks, and large messy fish push it up fast. Keep nitrate under 20 ppm.

Diet & Feeding#

Green Severums are omnivores with a strong vegetable bias. Their wild diet leans hard on fruit, seeds, plant matter, and small invertebrates picked from leaf litter. A captive diet that mirrors that ratio keeps them healthy and brightly colored.

Omnivorous Needs: Balancing Pellets with Vegetable Matter#

Plant matter should make up roughly half the diet. Spirulina-based pellets, blanched peas (skinned and quartered), zucchini medallions, and dried nori all work. Severums fed exclusively on protein-heavy foods are prone to digestive issues, faded color, and accelerated hole-in-the-head problems.

A high-quality cichlid pellet — New Life Spectrum Cichlid Formula or Hikari Cichlid Gold — works as the daily staple. Pellets sized for an adult cichlid (4 to 6 mm) get eaten without waste; flakes blow around and foul the water. Feed twice daily, only what the fish clear in two minutes.

Live and Frozen Foods: Bloodworms, Brine, and Mysis#

Rotate frozen mysis shrimp, frozen krill, and frozen bloodworms in 2 to 3 times per week. Live blackworms or earthworms are an occasional treat. Combined with a steady rotation of vegetables 3 to 4 times per week, this varied diet keeps body color rich and supports the immune system that wards off the lateral line erosion this species is prone to.

Tank Mates & Compatibility#

The Green Severum's reputation as a community cichlid is earned, but only within reason. Match by size, water requirements, and temperament.

Best Cichlid Companions: Geophagus, Blue Acara, and Angelfish#

The classic Severum tank pairs them with peaceful eartheaters (geophagus species) that work the substrate, blue acaras of similar size and temperament, and angelfish that share the biotope and the deep-bodied silhouette. The keyhole cichlid is another excellent peaceful South American cichlid that coexists with Severums in larger tanks. For keepers comparing Severum color forms, the gold severum is the captive-bred xanthic morph of the same species and shares identical care requirements.

Dither Fish: Large Tetras and Silver Dollars#

Schooling dither fish help Severums feel secure and reduce shy behavior. Silver dollars are the gold standard — peaceful, large enough to ignore, and fast enough to dodge any aggression. Bleeding heart tetras, Buenos Aires tetras, and Congo tetras all work well in 75-gallon-plus tanks. Bristlenose plecos and clown plecos handle algae and waste cleanup along the bottom.

Species to Avoid: Snack-Sized Fish and Hyper-Aggressive Cichlids#

Small tetras (neons, ember tetras, rasboras) are bite-sized and will eventually disappear into a Severum's mouth. Skip them. On the other end of the size spectrum, avoid Oscars, Jack Dempseys, green terrors, and large Central American cichlids — they bully Severums into hiding and stop them from eating. For a broader look at compatible options, see our freshwater fish overview.

Breeding the Green Severum#

Severums breed readily in captivity once a bonded pair forms, though raising fry to saleable size takes patience.

Identifying Pairs: Subtle Differences in Facial Markings#

Sexing Green Severums is easier than sexing Gold morphs because the wild coloration retains more of the patterning that distinguishes the sexes:

• Males develop more pointed dorsal and anal fins as they mature
• Females stay slightly smaller and rounder with shorter, more rounded fins
• Mature males show heavier facial markings — broken lines and spots around the eyes, gills, and operculum that females largely lack

The reliable approach to getting a pair is to buy six to eight juveniles, raise them together, and let them sort themselves out. A bonded pair will start defending a territory and ignore the others. At that point, rehome the extras.

Spawning Behavior: Substrate Cleaning and Egg-Guarding#

A bonded pair will pick a flat slate, large smooth rock, or piece of driftwood and clean it obsessively before spawning. The female lays 200 to 1,000 eggs in neat rows, and both parents guard the clutch. Eggs hatch in 3 to 5 days at 80 degrees F. The parents move the wrigglers to a pre-dug pit in the substrate and continue guarding for weeks.

Fry feed initially on a parent-secreted slime coat (the same behavior discus is famous for) before accepting baby brine shrimp and crushed flake at about 7 to 10 days post-hatch.

Common Health Issues#

Green Severums are hardy under stable conditions. The two issues that show up most often are both linked to long-term water quality and diet.

Hole-in-the-Head (HITH) Disease: Causes and Prevention#

Hole-in-the-head, also called head and lateral line erosion (HLLE), shows up as small pits or cavities along the head and the lateral line. The exact cause is debated, but the consensus points to a combination of poor water quality (chronically elevated nitrate), nutritional deficiency (too little vegetable matter, too few vitamins), and stress.

Prevention is the same as the cure — stay aggressive with water changes, keep nitrate under 20 ppm, feed a varied diet with consistent vegetable matter, and use a quality vitamin supplement (Seachem Vitality or Selcon) once a week. If pits start forming, immediate water-quality intervention will usually arrest the progression and allow slow healing over months.

Ich and External Parasites: Treatment in a Large Tank#

Ich (white spot disease) is the standard freshwater parasite to watch for, especially after introducing new fish. Treat at 86 degrees F with a copper or malachite green-based medication, or with heat alone (raise the temperature to 86 degrees F and hold for two weeks). Severums tolerate the higher temperature well.

Quarantine all new tankmates for 4 weeks in a separate 20 or 30-gallon tank before adding them to a Severum aquarium. A bare-bottom QT with a sponge filter, a heater, and PVC pipe for cover catches the parasites and bacterial infections that ride in on new fish before they reach your display tank.

Where to Buy & What to Look For#

Green Severums are widely available in the trade, though wild-caught specimens are far less common than the captive-bred Gold morph. Quality varies dramatically between sources.

Selecting Healthy Specimens#

Buy juveniles in the 1.5 to 3-inch range. At that size, they ship and acclimate well, you can watch them grow into their full body, and they accept a varied diet from the start. A juvenile with a deep, well-rounded body shape is genetically programmed for the classic Severum silhouette — slender or torpedo-shaped juveniles rarely fill out the way you want them to. Look for clear, alert eyes, upright fins, and active swimming. Sourcing from a tank that holds multiple specimens lets you pick the most vigorous individual rather than taking whatever the bag yields.

Local Fish Store vs. Online#

Captive-bred Green Severums typically run $10 to $25 per juvenile at a local store, with wild-caught specimens occasionally available at higher price points. Online vendors offer a wider selection but with the standard tradeoffs — shipping stress, no chance to inspect the fish before purchase, and a higher acclimation curve for fish that arrive after 18 to 36 hours in a dark bag. For a fish you plan to keep for a decade, the inspection opportunity at a local store is worth the slight selection tradeoff.

For acclimation, drip-acclimate over 60 to 90 minutes — Severums coming from a different pH or hardness will stress quickly if you dump them straight into your tank water.

Quick Reference#

• Tank size: 75 gallons minimum for a single adult; 90 to 125 gallons for a pair or community
• Temperature: 75 to 84 degrees F (78 to 80 ideal)
• pH: 6.0 to 7.5 (tannin-stained Amazon biotope preferred)
• Hardness: 4 to 12 dGH (soft to moderately soft)
• Diet: Omnivore — quality cichlid pellets daily, vegetables 3 to 4 times per week, frozen foods 2 to 3 times per week
• Tankmates: Silver dollars, geophagus, angelfish, bristlenose plecos, blue acaras, larger tetras
• Avoid: Small tetras (food), Oscars and large aggressive cichlids (bullies), soft-leaved plants
• Difficulty: Intermediate — hardy once established, but big and long-lived
• Lifespan: 10+ years