Blue Gourami (Trichogaster trichopterus sumatra)

Choose the fish and dispatch size

The Blue Gourami is a freshwater labyrinth fish in the family Osphronemidae. This offer carries the established name Trichogaster trichopterus sumatra. FishBase now lists it as Trichopodus trichopterus and gives Three spot gourami as the common name. Its Asian range includes the Mekong basin in Laos, Yunnan, Thailand, Cambodia and Viet Nam, with introductions elsewhere. It reaches 15 cm standard length and suits a keeper who can provide a substantial planted aquarium, stable water and carefully screened companions.

A labyrinth organ allows gouramis to breathe atmospheric air, while their elongated pelvic-fin rays help them sense their surroundings. Those features do not reduce the need for a mature filter, stable water and enough swimming room. This is a substantial gourami rather than a small species for a compact aquarium, and its changing temperament deserves as much attention as its broad water tolerances.

Understand the offer

The size you select is the size supplied, not the adult size. A smaller supplied fish does not justify a smaller permanent aquarium, while XL is a label rather than a numerical adult-size promise. Use the live selector to choose the supplied size, then make every aquarium decision around the adult fish.

Sex is guaranteed only when the selected option explicitly states male or female. This Blue Gourami listing has no sex-guaranteed option.

The gallery images are representative, based on reference photographs of this species, so colours can look slightly different from the live animal.

Browse our gouramis and labyrinth fish collection to compare related fish. Before ordering, read the current delivery and Live Arrival Guarantee policy for dispatch days and claim terms.

Plan the aquarium around the adult size

Seriously Fish gives 150 mm standard length, an aquarium base of 90 × 30 cm and a volume of approximately 81 litres for this fish. Treat the footprint as a central requirement: length and width create swimming space and room for planted cover in a way that height alone cannot replace. FishBase independently gives a maximum of 15 cm standard length.

The aquarium should combine plants, floating cover and open swimming areas. This arrangement gives the fish cover without turning the whole surface into a dense barrier. Keep a clear route to the surface because the labyrinth organ is used to breathe atmospheric air. Gravel or sand can form the substrate, and live plants add useful structure.

Use the decisive figures together

The routine water figures are the overlap of FishBase’s environmental range, Seriously Fish’s aquarium guidance and OATA’s group guidance. They describe one connected setup, not independent permissions to compromise elsewhere. An aquarium that holds roughly 81 litres but has a much shorter base misses the stated footprint. Likewise, a suitable footprint still needs working filtration, stable temperature and compatible occupants.

Decide whether this setup fits

Temperament is the second major planning limit. Some individuals remain peaceful, while others become spiteful as they mature. Males are territorial and will squabble amongst themselves, becoming very aggressive when breeding. A Blue Gourami should therefore be chosen for an aquarium whose other fish are robust enough for that uncertainty, not added solely because the water values overlap.

A larger aquarium can make environmental conditions more stable and give more scope for planting and stocking decisions, but extra litres do not cancel aggressive behaviour. Use the 90 × 30 cm base and approximately 81 litres as the starting reference, then assess every additional gourami or companion against the actual footprint, cover and behaviour already present.

Mature the filter before the fish arrives

Prepare a fully filtered aquarium before adding the fish. The RSPCA explains why biological filtration is essential: fish release toxic ammonia, beneficial bacteria convert it to nitrite, and another stage converts nitrite to the safer nitrate. A filter needs time and suitable conditions to establish those bacterial populations.

Use our first tropical aquarium guide to plan the setup and maturation process before livestock arrives. Do not treat clear-looking water as proof that the filter is ready. Ammonia and nitrite are dissolved wastes, so readiness is decided through testing rather than appearance.

Complete the pre-arrival checks

1. Install the permanent equipment. Run the filter and heater intended for the occupied aquarium rather than relying on an unfiltered holding container.
2. Mature the biological filter. Beneficial bacteria must be established before the fish adds waste.
3. Test the water. Confirm ammonia and nitrite are both 0 mg/l before adding the Blue Gourami.
4. Set the aquarium range. Keep temperature, pH and hardness within the aquarium guidance for this fish.
5. Finish the layout. Provide planted and floating cover together with open swimming room and surface access.
6. Review the occupants. Check adult sizes, temperaments and feeding competition before the new fish joins them.

Add fish to a mature aquarium gradually. Every extra animal and every increase in feeding raises the load on the filter. Stocking too quickly can create new tank syndrome when the bacterial population cannot process the increased waste, allowing ammonia or nitrite to rise.

A mature filter remains a living part of the aquarium rather than a one-off setup task. Chlorine or chloramine can damage its bacteria, replacement water must be conditioned, and blockages can reduce its performance. Weekly tests and maintenance are therefore part of keeping the aquarium mature after the Blue Gourami arrives.

If the aquarium has recently been set up, heavily cleaned, medicated or stocked with several fish, test before proceeding. The safe decision is the one based on measured ammonia and nitrite, not the number of days the equipment has been running.

Hold stable water within the aquarium range

For routine aquarium care, keep the temperature at 24–28 °C, pH at 6.0–8.0 and general hardness at 5–12 dGH. This is the overlap of FishBase’s environmental range, Seriously Fish’s aquarium guidance and OATA’s group guidance. These ranges show adaptability, but they do not make rapid changes harmless. Choose conditions that suit the whole aquarium and keep them stable rather than repeatedly moving between the limits.

OATA’s gourami and paradise-fish sheet gives group guidance: ammonia and nitrite should be 0 mg/l, while nitrate should not rise more than 20 mg/l above the normal tap-water level. It gives 20–28 °C, pH 6.0–8.0, 4–12 dGH and 3–10 dKH for the group; these are not a species-specific optimum.

Give each measurement a job

Read our water chemistry guide for the role of each value, then use the water matcher to compare measured aquarium water with the stated ranges. Test the tap water as well as the aquarium when using the nitrate limit, because the instruction is based on the rise above the normal tap-water level.

Do not use the pH or hardness span as a reason to alter water unnecessarily. If the aquarium is within range, stable and supporting suitable companions, consistency is the practical goal. When a result moves unexpectedly, check the test method, temperature, recent water changes, feeding and filter operation before making another change.

Any ammonia or nitrite reading requires prompt attention. Pause further stocking, test again carefully and check the filter for interrupted flow or maintenance damage. Visible distress and an abnormal test result should be treated as connected warning signs until water quality has been restored.

Combine cover with open swimming space

Build the layout around a base of at least 90 × 30 cm and approximately 81 litres. A planted aquarium with floating cover and open areas for swimming suits this fish. The aim is not maximum plant density; it is a deliberate balance between shelter, visual structure, surface cover and unobstructed movement.

Divide the aquarium by function

Review the layout from the fish’s point of view. One completely open aquarium lacks the recommended cover, while a solid mass of plants can remove the open swimming areas called for in the species guidance. Create more than one type of space instead: planted margins or clusters, partial floating cover and a clear route through the aquarium.

Filtration must be sized to the aquarium. At approximately 81 litres, Seriously Fish uses a turnover of four to five times the aquarium volume per hour and gives a filter rating of 325–405 litres per hour. Treat the manufacturer’s rating as a selection reference, then check that the installed filter remains clear of blockages and continues moving water.

For an aquarium of about 81 litres, a heater of roughly 100–150 W is suggested when the surrounding room is around 20 °C. Room temperature matters: the heater has to bridge the difference between the room and aquarium, so monitor the result with a thermometer and hold the routine target of 24–28 °C rather than assuming wattage alone guarantees it.

Keep the filter intake, outlet and heater clear enough to function as intended. Plants should support the fish without blocking equipment or eliminating surface access. If the layout changes through plant growth, trim or reposition the cover so the original balance of shelter and swimming room remains.

Extra aquarium volume can improve stability, but footprint and layout still need direct attention. A taller aquarium does not automatically create more horizontal swimming room, and powerful equipment does not replace planting. Judge each part by the need it serves.

Feed a varied omnivore once daily

Blue Gouramis are generalised omnivores. In nature, the species eats terrestrial and aquatic plant matter, algae, small invertebrates, zooplankton and detritus. In the aquarium it accepts most foods, so the practical task is to provide variety without allowing excess food to pollute the water.

Use a good-quality flake, granule or pellet as the regular prepared food. Include an algae-based food to reflect the plant and algae component of the species’ diet. Small live or frozen foods such as daphnia, small bloodworm or tubifex can add variety.

Build a controlled feeding routine

• Frequency: feed once a day.
• Portion: offer only what the fish can eat within a few minutes.
• Base foods: choose a suitable flake, granule or pellet.
• Plant component: include an algae-based food.
• Variety: rotate small live or frozen daphnia, bloodworm or tubifex.
• Adjustment: reduce the next portion if food remains after the feeding period.

Watch whether the Blue Gourami reaches the food rather than judging the ration only by what disappears. In a mixed aquarium, fast companions may consume much of the portion while a slower fish receives little. A feeding session succeeds when the intended fish eats and the aquarium is not left with an accumulation of food.

Overfeeding creates two linked problems. The fish receives more food than required, and uneaten material breaks down into waste. That extra waste increases the demand on biological filtration and can contribute to unhealthy water conditions. More food is therefore not a substitute for better access or a more suitable stocking plan.

Use the few-minute limit as an observation window. If everything disappears immediately but the gourami does not feed, review competition and food placement before increasing the total amount. If food remains, stop adding more and make the next serving smaller. These responses keep feeding tied to behaviour rather than a fixed pinch that may be too large or too small.

A change in appetite is also a health signal. Reduced intake or loss of interest in food should prompt a water test and a wider check of swimming, breathing, colour, body condition and social behaviour. Keep the menu consistent enough that a genuine change is easy to recognise.

Introduce the fish to a ready aquarium

Make the important introduction decisions before the fish arrives. Confirm that the aquarium is mature, filtered and large enough for the adult fish; test ammonia and nitrite at 0 mg/l; set temperature within 24–28 °C; and review every established occupant for size and temperament.

Use a first-week checkpoint plan

Increase the aquarium population slowly. Beneficial bacteria respond to the waste load created by fish and feeding, and adding several animals in quick succession can outpace that response. The result can be new tank syndrome, with ammonia or nitrite reaching unhealthy levels.

Observation should be specific. Note whether the fish swims normally, reaches the surface, uses both planted and open areas, and feeds. Check whether existing fish chase it, whether it drives timid fish into hiding, or whether fin-nipping appears. Temperament can vary between individuals, so behaviour in this aquarium is more useful than a generic community label.

Do not add another fish merely because the first few hours look calm. The species may change as it settles and may become more aggressive as it matures. Let water tests, feeding response and social behaviour establish a clear baseline before changing the stocking plan.

If the fish stops feeding, changes colour markedly, breathes unusually, hangs at the surface, sits on the bottom or swims erratically, test the water promptly. A water-quality problem can affect several fish and needs to be identified before adding anything else.

Keep the first week simple. Maintain the established temperature and feeding routine, avoid unnecessary stocking changes, and record test results and observations. That gives you a useful comparison if appetite, breathing or temperament later changes.

Protect the filter during weekly care

Carry out a partial water change of 25% at least once every week. Use a siphon to remove solid waste from the substrate, and treat replacement tap water with a conditioner that removes chlorine or chloramine before it enters the aquarium.

Test the water at least weekly. Ammonia and nitrite should remain at 0 mg/l, while nitrate should not exceed 20 mg/l above the normal tap-water level. Record the result so a gradual change is visible before it becomes a larger problem.

Follow a repeatable maintenance order

1. Test first. Measure the aquarium before the water change so the result describes the conditions the fish experienced.
2. Remove 25%. Siphon water and collect solid waste from accessible substrate.
3. Prepare replacement water. Treat it for chlorine or chloramine before use.
4. Check equipment. Look for filter blockages and confirm the heater is holding the intended temperature.
5. Clean filter media only when needed. Rinse it lightly in removed aquarium water rather than under the tap.
6. Observe afterwards. Confirm normal flow, temperature, swimming and breathing.

Tap water can contain chlorine or chloramine that harms the beneficial bacteria living in filter media. Rinsing media under the tap risks reducing the population responsible for processing ammonia and nitrite. Removed aquarium water provides a safer rinsing medium and avoids an unnecessarily severe clean.

Do not make the filter look spotless at the expense of its biological function. The goal is to clear blockages and preserve flow while retaining the bacteria that keep the nitrogen cycle working. Light rinsing is different from stripping and sterilising every component.

Use the weekly routine to inspect the whole setup. Plant growth may have blocked the outlet or covered too much of the surface; waste may have collected in a sheltered area; or the temperature may have moved from its normal level. Correct the specific issue while preserving stable conditions elsewhere.

If ammonia or nitrite appears, postpone further stocking and inspect the filter, recent feeding and maintenance history. Repeat the test carefully and continue monitoring the fish. A weekly routine is the minimum rhythm; an abnormal result or visible change justifies an additional test.

Respond to changes before they escalate

Learn the Blue Gourami’s normal swimming, colour, appetite, breathing and use of cover. Individual fish differ, so a change from that established pattern can be more informative than a single isolated posture.

Pair each warning sign with a first action

Water testing is the first response because ammonia and nitrite are toxic and can affect more than one animal. Check the filter for blockages or interrupted operation, review any recent cleaning, and compare the result with previous weekly tests.

Social stress also deserves direct attention. Some Blue Gouramis become more aggressive as they mature, while timid companions may hide or lose access to food. A change in aggression, damaged fins or persistent hiding should trigger a fresh compatibility assessment rather than an automatic increase in feeding.

Appearance and behaviour can point to a problem without identifying its cause. Avoid choosing a treatment from one sign alone. Test the aquarium, note every affected fish and the order in which changes appeared, then contact us for health guidance when the change persists or the animal appears distressed.

Continue normal essential care while gathering those observations. Keep temperature stable, preserve filtration and avoid adding new fish. Record water results, appetite and visible changes so progress can be judged against a clear baseline rather than memory.

Good observation is brief but regular. A few focused checks during feeding and maintenance reveal whether the fish is eating, breathing normally, moving through the aquarium and interacting without escalating conflict.

Screen companions for robustness

Do not treat the Blue Gourami as a universally peaceful community fish. Some individuals remain peaceful, while others become spiteful as they mature. Males are territorial and will squabble amongst themselves, becoming very aggressive when breeding.

Seriously Fish recommends robust companions and names barbs, larger characins, loricariids, loaches and other medium or large gouramis as examples. These are screening categories rather than guaranteed combinations. Species, adult size, individual temperament, aquarium footprint and the particular mix of occupants still decide whether a combination works.

Use a conditional compatibility screen

Start with the adult fish, not the supplied size. A companion that appears large beside a 2–3 cm Blue Gourami may become comparatively small once the gourami reaches up to 15 cm standard length. Compare adult sizes and adult behaviour before selecting either fish.

Then consider temperament in both directions. The Blue Gourami may intimidate a timid fish, while a fin-nipping companion may damage the gourami. A robust label alone does not answer whether a fish is predatory, territorial, highly active or likely to compete aggressively at feeding time.

Finally, assess the physical aquarium. The 90 × 30 cm base and approximately 81-litre reference apply to the Blue Gourami setup, but every added species brings its own space and social needs. More fish require more capacity and a filter able to process the resulting waste.

Build the stocking plan one step at a time

One purchase supplies one Blue Gourami, which supports a cautious starting plan. Do not buy several simply to create a fixed group. Same-species males will squabble amongst themselves, individual temperament varies, and aggression can increase with maturity or breeding behaviour.

Answer five questions before adding the fish

1. Is the aquarium large enough? Use at least a 90 × 30 cm base and approximately 81 litres for the Blue Gourami, then allow for every other species.
2. Is the filter mature? Ammonia and nitrite must be 0 mg/l before another fish increases the waste load.
3. Are the companions robust? Avoid timid fish, fish small enough to be eaten and likely fin-nippers.
4. Is there structured cover? Combine plants and partial floating cover with open swimming room.
5. Is there a fallback plan? Make the decision before conflict prevents a fish from feeding or using the aquarium normally.

A single individual avoids the direct challenge of planning a same-species group, but it does not make the wider community automatically safe. Watch how it behaves with established fish and how they respond to it. Persistent chasing, increased hiding, fin damage or loss of feeding access means the original compatibility decision needs review.

When considering more than one gourami, do not base the plan on an assumed sex. Use the aquarium’s footprint, cover, existing territories and observed behaviour instead. Other medium or large gouramis appear among the potential robust companions in the species guidance, but they remain a cautious choice because territorial interactions can vary.

Add livestock gradually and allow the aquarium to establish a new baseline between changes. Check water quality, feeding access and social behaviour before making the next addition. This separates the effect of each stocking decision and gives the biological filter time to respond to extra waste.

For a stocking assessment, contact us with the aquarium dimensions, volume, current temperature, recent ammonia and nitrite results, and the full species and numbers already kept. Those details allow a more useful screen than a list of common names alone.

No named companion is universal. Robust barbs, larger characins, loricariids and loaches are starting categories supported by the species guidance; each proposed species still needs its own adult-size, water, social and temperament check.

Answer the key buyer questions

How big does the Blue Gourami get?

The Blue Gourami reaches up to 15 cm standard length. Plan its permanent aquarium around that adult size rather than the size supplied.

What size aquarium does Trichogaster trichopterus need?

Plan a base of at least 90 × 30 cm and approximately 81 litres, with live plants, partial floating cover, open swimming areas, a mature filter and surface access.

How many Blue Gouramis should I keep together?

Start cautiously with one fish rather than buying to a fixed group number. Males will squabble amongst themselves and individual temperament varies, so assess the aquarium footprint, cover and behaviour before considering more gouramis.

Is this fish suitable for a beginner?

Seriously Fish recommends it to beginners with reservations about temperament. It tolerates broad water conditions, but the keeper must provide a mature filtered aquarium and be ready to manage aggression that may develop as it matures.

What should I feed a Blue Gourami?

Feed a good-quality flake, granule or pellet once daily, including an algae-based food. Offer only what it eats within a few minutes, with small live or frozen daphnia, bloodworm or tubifex for variety.

What temperature and pH does it need?

The FishBase, Seriously Fish and OATA overlap is 24–28 °C, pH 6.0–8.0 and 5–12 dGH. Keep ammonia and nitrite at 0 mg/l and maintain stable conditions within those ranges.

Is the Blue Gourami aggressive or likely to have fin problems?

Some individuals remain peaceful, while others become spiteful as they mature; males are territorial and will squabble amongst themselves. Avoid likely fin-nippers because they may damage the gourami’s fins.

Which animals can live with this fish?

Screen robust barbs, larger characins, loricariids and loaches individually. Avoid timid fish, fish small enough to be eaten and likely fin-nippers; no named companion is universally suitable.

How does the Blue Gourami arrive alive in the UK?

Start filming every delivery with the parcel still sealed, then record continuously as it is opened and while the fish remains inside the sealed bag. Someone must be present to receive the parcel. Float the bag for 20–30 minutes before releasing the fish, and never pour the bag water into the aquarium.

Consult the care references

• FishBase: Trichopodus trichopterus — accepted name, synonym, family, distribution, environmental range and maximum standard length.
• Seriously Fish: Trichopodus trichopterus — aquarium footprint, volume, water conditions, layout, diet and behaviour.
• OATA: Gouramis and paradise fish — group husbandry, feeding, introduction, maintenance and warning signs.
• RSPCA: Aquarium environment — biological filtration and aquarium waste processing.