Blue Gourami Care Guide: Tank Size, Diet, and Tank Mates

Species Overview#

Blue gouramis (Trichopodus trichopterus) are one of the most widely sold freshwater labyrinth fish in the US hobby. They have been a staple of community tanks since the 1950s for one reason: they are tough, attractive, and forgiving of beginner mistakes that would kill more delicate species. Their steel-blue body and two dark lateral spots make them instantly recognizable on any fish store wall.

The species is native to slow-moving, heavily vegetated waters across Southeast Asia. That history shapes everything about how you should keep them — warm water, dense planting, calm surface, and tank mates that will not pick a fight with a 5-inch fish that grows bolder with age.

Adult size

5–6 in (13–15 cm)

Lifespan

4–6 years

Min tank

20 gallons (single); 30 gallons (pair)

Temperament

Semi-aggressive (males)

Difficulty

Beginner

Diet

Omnivore

Natural Habitat & Origin#

Wild T. trichopterus populations live in Thailand, Malaysia, Vietnam, Cambodia, and parts of Indonesia. They occupy slow rivers, swamp forests, flooded paddies, and irrigation ditches — habitats that go warm, stagnant, and oxygen-poor during the dry season. To survive, the species evolved a labyrinth organ that lets them gulp atmospheric air directly. That single adaptation is why blue gouramis can shrug off conditions that would kill tetras and rasboras outright.

Appearance & Color Variants#

The wild-type fish is silvery blue with two dark spots aligned along the body — one mid-flank and one at the base of the tail. Selective breeding has produced several common variants you will see at retail:

• Three Spot (wild type): Pale silver-blue with two clean dark spots.
• Opaline: Marbled blue with swirled darker patterning across the body, no defined spots.
• Gold: Yellow-orange body with faint vertical bars.
• Cosby: Marbled blue with extra-dark patterning, often sold as "platinum" variants in some shops.

All four are the same species and interbreed freely. Pricing varies $4–$10 depending on color, with Opalines usually commanding the highest tag.

Size & Lifespan#

Adults reach 5–6 inches under good conditions, with males slightly larger and more elongated than females. In captivity, expect a 4–6 year lifespan. Fish kept in cramped 10-gallon setups rarely make it past three years; a properly sized 30-gallon-plus tank with stable parameters routinely produces fish that hit the upper end of that range.

Water Parameters & Tank Requirements#

Blue gouramis are forgiving, but "forgiving" is not the same as "indestructible." Get the tank size and surface access right, and the rest is straightforward.

Ideal Water Conditions#

The species tolerates a wide parameter range, which is one reason it became a beginner staple. Stability matters more than hitting an exact number.

Cycle the tank fully before adding livestock. Zero ammonia, zero nitrite, measurable nitrate — that is the only safe baseline for a new aquarium.

Minimum Tank Size & Layout#

A 20-gallon tank is the absolute minimum for a single blue gourami. A 30-gallon long is the practical minimum for a pair, and a 40-gallon-plus tank is what you want if you plan to add tank mates. Length matters more than height — these fish patrol horizontally and need swimming room.

Aquascape with tall background plants like Amazon sword, vallisneria, and hornwort. Add floating cover (Amazon frogbit, red root floaters, or a clump of hornwort left untethered) so females and subdominant fish have a place to escape male attention. Leave open mid-tank swimming space; do not fill every square inch with hardscape.

Filtration & Surface Access#

A hang-on-back filter rated for your tank volume works well. Sponge filters are fine for breeding setups. Whatever you choose, baffle the output if it produces visible surface chop — blue gouramis dislike strong flow and need a calm patch of surface to gulp air comfortably.

Diet & Feeding#

Blue gouramis are omnivores and will eat almost anything that fits in their mouth. The mistake new keepers make is feeding too much, not too little.

What Blue Gouramis Eat#

Build the diet around a quality flake or micro pellet as the daily staple. Supplement two or three times per week with frozen bloodworms, brine shrimp, or daphnia for protein and enrichment. Add blanched zucchini or shelled peas once or twice weekly — vegetable matter helps prevent constipation, which is a common problem in overfed gouramis.

Live foods like mosquito larvae or live brine shrimp are excellent for conditioning breeding pairs but are not required for daily care.

Feeding Schedule & Quantity#

Feed adult blue gouramis once or twice daily. Each feeding should be the amount your fish finish in two to three minutes. Anything left after that is fueling ammonia, not your fish.

Skip one feeding per week. A weekly fasting day clears the digestive tract, reduces bloat risk, and matches the boom-bust feeding rhythm these fish would experience in the wild.

Tank Mates & Compatibility#

Blue gouramis are listed as community fish, but the "semi-aggressive" label is real. Adult males in particular grow territorial and will harass smaller, slower fish.

Good Community Companions#

Pair blue gouramis with fish that occupy a different water column level and can handle themselves around a 5-inch tank mate:

• Corydoras catfish — bottom-dwellers that stay out of the gourami's territory entirely.
• Larger tetras — black skirt tetras, lemon tetras, and rummy-nose tetras hold their own in mid-water.
• Harlequin rasboras — calm, peaceful, share the same parameter range.
• Mollies and platies — tough live-bearers that ignore gourami posturing.
• Bristlenose plecos — armored algae eaters that do not provoke aggression.
• Kuhli loaches — nocturnal bottom-dwellers that stay out of the way.

Species to Avoid#

• Other male gouramis — T. trichopterus males will fight any other male gourami in a tank under 55 gallons. One male per tank, no exceptions.
• Bettas — both are labyrinth fish with overlapping territorial instincts. The pairing fails far more often than it succeeds.
• Fin nippers — tiger barbs and serpae tetras will shred the long thread-like ventral fins blue gouramis use to feel their way around.
• Slow, long-finned fish — angelfish, fancy guppies, and bettas all get harassed.
• Aggressive cichlids — convicts, jewels, and Jack Dempseys will outcompete and eventually kill blue gouramis.

For a side-by-side look at species, water parameters, and stocking ratios across the family, see our gourami fish care guide. The opaline gourami and dwarf gourami pages cover the most common alternatives, and kissing gourami and honey gourami profiles round out the family.

Breeding Blue Gouramis#

Blue gouramis are bubble-nesters, and home breeding is achievable with a dedicated 20-gallon setup.

Sexing Males vs. Females#

Wait until your fish are 3–4 inches before sexing. Males have a long, pointed dorsal fin that extends well past the base of the tail. Females have a shorter, rounded dorsal fin and a rounder belly when carrying eggs. Males also display more saturated coloration, which intensifies during breeding.

Bubble Nest Spawning Process#

Move a conditioned pair to a 20-gallon breeding tank with a water level lowered to about 8 inches and the temperature raised to 78–82°F. Add floating plants — duckweed, frogbit, or hornwort — to give the male anchor points for his nest.

The male builds a bubble raft at the surface over one to two days, then displays in front of the female. When she is ready, she swims under the nest, the male wraps around her in a nuptial embrace, and eggs are released and fertilized. The male catches sinking eggs and spits them into the nest. A single spawn can produce 500 to 800 eggs.

Remove the female immediately after spawning is complete. The male becomes aggressive while guarding the nest and will kill her if she is left in the tank.

Raising Fry#

Eggs hatch within 24–36 hours at 80°F. Fry are free-swimming about three days later. Remove the male at this point.

Feed fry infusoria or commercial liquid fry food for the first 7–10 days, then transition to baby brine shrimp and crushed flake. Fry grow slowly — expect 4–6 months before they reach a sellable 1.5-inch size. A separate grow-out tank with a sponge filter keeps the fastest-growing fish from outcompeting their siblings.

Common Health Issues#

Ich & Velvet#

Ich (white spot disease): white salt-grain spots on fins and body, flashing against decor, clamped fins. Treat by raising temperature gradually to 82–84°F over 24–48 hours and dosing aquarium salt or a malachite-green-based medication. Blue gouramis tolerate heat treatment well.

Velvet (Piscinoodinium): gold or rust-colored dust on the body, often visible only under a flashlight in early stages. Velvet progresses faster than ich and is more dangerous. Treat with a copper-based medication, but remove any shrimp or snails first — copper is lethal to invertebrates.

Hole-in-the-Head & Bacterial Infections#

Hole-in-the-head appears as small pits or eroded patches on the head, typically just above the eyes. The condition is linked to poor water quality, dietary deficiencies, and high nitrate levels. Treatment involves correcting water parameters, large daily water changes, and improving the diet with vitamin-enriched live or frozen foods.

Bacterial infections show up as red streaks on fins, ulcers on the body, or cottony patches. They almost always follow a stress event — a temperature swing, an aggressive tank mate, or a missed water change. Perform a 50% water change, fix the underlying problem, and treat with a broad-spectrum antibiotic like kanamycin if symptoms persist after 48 hours.

Labyrinth Organ Complications#

Cold drafts above the tank cause respiratory inflammation in labyrinth fish. Symptoms include heavy, labored breathing at the surface, gasping, and reluctance to gulp air. Prevention is simple: keep the tank lid closed during winter, position the aquarium away from windows and AC vents, and maintain a half-inch warm air gap between the water line and the lid.

Where to Buy & What to Look For#

Blue gouramis are one of the most widely available freshwater fish in the US. That ubiquity is a double-edged sword — they are everywhere, but quality varies wildly between sources.

Ask the staff if they quarantine new arrivals. A store that holds incoming fish for one to two weeks before selling them dramatically reduces your risk of bringing parasites or bacterial infections into your tank.

Price Range & Availability#

Expect to pay $4–$10 per fish at most US retailers. Wild-type three-spot fish are at the low end, with Opaline and Gold variants commanding $7–$10. Specialty Cosby and platinum morphs can run higher at boutique stores.

Acclimation#

Float the bag in your tank for 15–20 minutes to equalize temperature, then drip-acclimate over 30–45 minutes by slowly adding tank water. Net the fish out and discard the bag water — never pour store water into your display tank, since it can carry pathogens. See our how to acclimate fish guide for the full step-by-step.

For more on the broader family, see our gourami fish care guide, or browse the full freshwater fish overview.

Quick Reference#

• Tank size: 30 gallons minimum for one or a pair; 40+ for community
• Temperature: 72–82°F (22–28°C)
• pH: 6.0–8.0
• Hardness: 5–35 dGH
• Diet: Omnivore — flake or pellet daily, frozen bloodworms/brine shrimp 2–3x weekly, vegetables 1–2x weekly
• Tankmates: Corydoras, larger tetras, harlequin rasboras, mollies, bristlenose plecos
• Avoid: Other male gouramis, bettas, tiger barbs, angelfish, aggressive cichlids
• Stocking: One male per tank, paired with one or two females
• Difficulty: Beginner
• Lifespan: 4–6 years