Glowlight Danio (Danio choprai)

Choose an active social danio

The Glowlight Danio (Danio choprai) is a small freshwater danio from the Irrawaddy in northern Myanmar that reaches 3.1 cm standard length. It suits a prepared keeper who can provide a proper social group, a long swimming area and stable aquarium conditions. This generally peaceful species can live in a well-furnished community, but its constant movement means the aquarium must be planned around activity as well as body length.

FishBase records this tropical, benthopelagic danio from northern Myanmar and gives a maximum recorded length of 3.1 cm standard length. FishBase now lists it as Danio choprae and treats Danio choprai as a synonym. It places the species in the family Danionidae and assesses it as Least Concern.

Decide whether the swimming style fits

Small body size does not make this a fish for a cramped container. The decisive question is whether the aquarium offers enough horizontal room for a continuously moving group. A rectangular base of at least 80 × 30 cm gives the fish a practical swimming route while leaving space for plants, wood or rocks around the margins.

OATA describes danios broadly as active shoaling fish and popular starter fish, but success still depends on preparing the aquarium before introducing livestock. A working biological filter, suitable water, a secure cover and enough members of the same species are essential parts of that preparation.

Select the dispatch size and quantity

One purchase supplies one animal in the size selected. The live size selector carries 1 cm and 2–3 cm choices, so set the quantity to the number of individual fish required rather than expecting a pair or ready-made group.

The size you select is the size supplied, not the adult size. Plan the permanent aquarium around a maximum recorded length of 3.1 cm standard length, the activity of the whole group and the space taken by every other resident. The smaller dispatch measurement never reduces the adult swimming-space requirement.

Build the social plan before choosing quantity

The species profile recommends a group of at least 8–10 specimens. For a new group, begin with no fewer than eight and aim for ten where the aquarium can support them. One individual can join a suitable established group, but one should not be planned as a solitary display fish.

Sex is guaranteed only when the selected option explicitly states male or female. This Glowlight Danio 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.

Do not use the dispatch measurement to estimate sex, maturity, origin or final colour. Select by the aquarium already prepared for the complete group, including its adult space, filtration and water requirements.

Check the decisive care numbers

The Seriously Fish species profile gives an aquarium base of 80 × 30 cm or larger for this active fish, with an approximate volume of 72 litres. Its routine aquarium range is 16–26°C, pH 6.0–8.0 and hardness of 1–12 dGH.

Those outer limits are not targets to move between. Choose stable values inside all three ranges and compare them with the needs of every intended resident. If another species needs conditions outside the overlap, do not combine the two merely because both are described as peaceful.

Use the whole plan, not one isolated number

A tank can meet the volume figure while offering a poor shape for swimming. Give priority to the stated base dimensions, then account for the space displaced by rocks, wood and dense planting. Preserve a clear route rather than filling the entire middle of the aquarium with décor.

Water compatibility must be checked with measurements rather than appearance. Test the aquarium and compare the results with the stated range using the Water Parameter Matcher. Where the values overlap, keep them steady instead of repeatedly adjusting towards a single decimal.

Build the aquarium around swimming space

Start with a base of at least 80 × 30 cm and an approximate volume of 72 litres. These dimensions are required for the species because it is active, even though its recorded adult length is small. Increase the aquarium plan when other fish, substantial décor or a larger Glowlight Danio group will share the same water.

Divide the layout into useful zones

• Open route: preserve a clear swimming lane through the aquarium.
• Planted shelter: place plants around the sides or rear rather than filling every open area.
• Structured margins: use rocks, gravel, water-worn boulders, roots or branches to create cover away from the main route.
• Calmer areas: direct outlets so the fish can move away from the strongest flow.
• Secure top: fit a close cover and inspect openings around cables and pipework.

A heavily planted arrangement with a darker substrate can provide an effective setting. A flowing-river or stream-style layout is another supported option, using variably sized rocks and gravel with larger water-worn stones. Hardy plants such as Microsorum, Bolbitis or Anubias can be attached to wood or rock instead of occupying the swimming lane.

Additional filter outlets or powerheads may provide flow, but torrent-like conditions should be avoided. Small danionins occupy calmer stretches and marginal zones in nature, so arrange circulation across the aquarium rather than forcing the group to remain in one harsh jet.

Check the cover from the fish’s perspective

Members of this genus are accomplished jumpers and can pass through surprisingly small gaps. Inspect the cover after every maintenance session, especially where cables, hoses or filter returns enter. Replace the lid correctly before restarting normal activity around the aquarium.

If décor leaves only a short route, simplify the centre rather than relying on the litre figure alone. The aquarium should let the whole group swim, turn and move between cover and open water without being confined to narrow pockets.

Hold water inside the species range

Maintain a stable temperature from 16–26°C, pH from 6.0–8.0 and general hardness from 1–12 dGH. Measure the aquarium rather than assuming that tap water, room temperature or clear-looking water is suitable. The water chemistry guide explains what the principal test results mean and why they matter.

Choose a point within the range that also suits every companion. For example, a measured temperature of 24°C falls inside 16–26°C, but it is useful only when the other residents can also be kept at 24°C. Apply the same overlap test to pH and hardness.

Keep toxic waste at the action boundary

OATA’s general danio guidance gives zero mg per litre for ammonia, zero mg per litre for nitrite and nitrate no more than 20 mg per litre above the normal tap-water level for the group. Use those waste limits alongside the decisions made from this fish’s aquarium range.

Test at least once each week and whenever behaviour changes. A sudden shift in swimming, breathing, colour or feeding should trigger water tests before any treatment is considered. Record the measurements so gradual changes are easier to recognise.

Replace water with conditioned tap water and avoid abrupt changes in temperature or chemistry. Weekly measurements are most useful when they lead to consistent action: remove waste, maintain the filter, keep stocking controlled and correct a measured problem rather than chasing a theoretical perfect value.

Protect the biological filter

A well set up and maintained biological filter is essential. The RSPCA explains that fish release toxic ammonia; filter bacteria convert it to nitrite, which is also toxic, and then to the safer nitrate. The aquarium must therefore be prepared around a functioning bacterial population rather than clear water alone.

If this is your first aquarium, complete the steps in our first tropical tank guide before introducing livestock. Adding fish before the filter can process their waste risks ammonia and nitrite rising faster than the bacterial population can respond.

Match flow to a 72-litre plan

For an aquarium of about 72 litres, the species profile uses a turnover of four to five times the aquarium volume per hour and points to a filter rated around 290–360 litres per hour. Ratings are a planning reference: décor, media loading and blockages can affect the movement seen in the aquarium.

• Distribute the outlet so it circulates water without creating torrent-like conditions.
• Keep some calmer water beside plants, wood or rocks.
• Check the filter for blockages as part of weekly maintenance.
• Confirm that the unit restarts after cleaning or a power interruption.
• Watch the group for an abrupt move towards the surface or away from its normal swimming area.

Clean without stripping away the bacteria

When media needs cleaning, rinse it lightly in aquarium water removed during a partial water change. Do not rinse it under the tap because chlorine or chloramine may kill beneficial bacteria. Avoid replacing all established media at the same time.

Increase livestock numbers slowly. OATA warns that stocking too quickly can create new tank syndrome when the biological filter cannot process the extra waste and feeding load. A social species still needs its proper group, so prepare enough mature filtration for that group rather than using prolonged solitary keeping as a cycling method.

Feed small foods once a day

In nature, the Glowlight Danio is thought to prey chiefly on insects and their larvae. In the aquarium it accepts most foods. Use a good-quality dried product as the staple and supplement it regularly with small live or frozen foods such as bloodworm, Daphnia and Artemia.

OATA’s feeding schedule for danios is once a day, giving only what the fish can eat within a few minutes. This creates a clear portion test: if food remains after the group has stopped feeding, reduce the next portion rather than allowing leftovers to break down.

Match the meal to the mouth

Observe actual feeding rather than relying on the amount added. A group may gather rapidly at one point while a less confident individual remains behind. Distributing an appropriately sized portion gives each fish a better opportunity to eat within the short feeding period.

Do not compensate for missed meals by adding a large quantity at once. Overfeeding leaves organic waste that can contribute to deteriorating water conditions. Keep the routine simple: one measured daily feed, a suitable staple, regular small live or frozen variety and prompt removal of leftovers.

Body condition and feeding response are useful daily checks. A reduced intake, loss of interest or noticeable change in weight belongs with the other warning signs in the health routine. Test ammonia and nitrite and review competition before changing foods repeatedly.

Use a weekly maintenance routine

Carry out a partial water change of 25% at least once every week. Use a siphon to remove solid waste from the substrate, especially where food and debris collect around stones, wood or dense planting. Treat replacement tap water with conditioner before it enters the aquarium.

Complete the same checks in a reliable order

1. Observe swimming, breathing, colour, condition and feeding response before disturbing the aquarium.
2. Test ammonia and nitrite and record both results; each should remain at zero mg per litre.
3. Check nitrate against the tap-water baseline and keep it within OATA’s stated limit.
4. Remove 25% of the water at least once each week while siphoning settled debris.
5. Rinse blocked filter media lightly in the removed aquarium water when necessary.
6. Add conditioned replacement water while avoiding a rapid temperature or chemistry change.
7. Check the filter has restarted and replace the close-fitting cover correctly.

A stable routine lets you compare one week with the next. If nitrate rises more quickly, waste accumulates sooner or the filter blocks repeatedly, review feeding and total stocking rather than treating each symptom as an isolated event.

Respond to changes, not just named illnesses

Different problems may share similar outward signs. Test the environment first, document what changed and speak to an aquatic veterinarian or experienced aquatic retailer when the cause remains unclear. Do not select treatment from one symptom alone.

Prepare for introduction and the first month

Prepare the complete aquarium and social plan before the fish arrives. Confirm that the base measures at least 80 × 30 cm, the volume is about 72 litres or more, the cover closes securely and the biological filter is operating. Test ammonia and nitrite and proceed only when both measure zero mg per litre.

Follow the arrival procedure

Read the current delivery and Live Arrival Guarantee policy before the delivery date.

1. Be present to receive the parcel because live fish cannot be left unattended.
2. Start filming before the parcel is opened and record one continuous take showing the sealed parcel, the parcel being opened and the fish still inside the sealed bag.
3. Float the bag for 20–30 minutes before releasing the fish.
4. Never pour the bag water into the aquarium.

Before introduction

• Measure temperature, pH and hardness and confirm that each sits within the planned range.
• Check that every intended companion overlaps with those conditions.
• Confirm that the selected quantity forms or joins a group of at least eight.
• Inspect gaps around the lid, cables, hoses and filter pipework.
• Have appropriately small dried food ready, with small live or frozen variety for the established routine.

First-week checkpoints

After introduction, observe swimming behaviour, breathing, colour, condition and response to food. Check whether all members can use the open route and move into calmer planted or structured areas. Investigate persistent isolation, erratic swimming, surface hanging or reduced feeding through water tests and observation.

Continue the once-daily feeding limit and remove uneaten food. Add other livestock only slowly because every increase in fish numbers and feeding requires the filter’s bacterial population to process more waste. Do not use one apparently normal test as a reason to complete several stocking changes at once.

First-month checkpoints

Carry out a 25% partial water change at least once each week and test the water at least weekly. Compare results over time rather than waiting for visible deterioration. Check filter flow, the secure cover and waste accumulation around the layout during every maintenance session.

By the end of the first month, the useful measure is consistency: zero ammonia, zero nitrite, controlled nitrate, steady feeding and normal movement across the group. If those conditions are not holding, pause further additions and correct the aquarium routine.

Keep a complete social group

The Glowlight Danio is a schooling species and should be kept in a group of at least 8–10 specimens. For practical planning, begin with no fewer than eight and aim for ten where the aquarium’s dimensions, filtration and total stocking permit. A lone fish should not be the intended permanent arrangement.

OATA’s broader danio guidance gives at least five, with more being better, and warns that danios kept singly or in groups that are too small often become stressed. Use the species profile’s higher figure for this fish, so five should not be the target for a new Glowlight Danio group.

Balance group size with aquarium capacity

Adding more members cannot repair inadequate swimming room or an immature filter. Work from both requirements at once: provide the social number and provide an aquarium capable of supporting it. If the aquarium cannot hold at least eight with an appropriate safety margin, choose a different plan rather than keeping this species alone.

Normal activity can be lively. Judge welfare through the complete pattern: whether fish feed, maintain condition, use the aquarium and show steady breathing. Persistent isolation, loss of appetite, damage or an abrupt change in swimming needs investigation through group size, water tests, layout and community interactions.

Screen every community companion

This species is generally very peaceful and can live in a well-furnished community, but no category is an automatic match. Screen each exact companion for temperature, pH, hardness, adult space, flow, feeding pace and behaviour before combining it with an active danio group.

The species profile identifies other small cyprinids, tetras, livebearers, rainbowfish, anabantoids, catfish and loaches as possible community categories. Treat these as candidates for individual checking rather than universal tank-mate promises. Species within the same category can differ substantially in size, behaviour and water needs.

Use a two-stage compatibility test

1. Water and space: find a stable overlap within 16–26°C, pH 6.0–8.0 and 1–12 dGH, then check that the combined community fits an 80 × 30 cm or larger base and the aquarium’s filtration capacity.
2. Behaviour and feeding: confirm that each resident can cope with constant danio movement and obtain food during a short feeding period.

OATA warns that active danios may stress more timid species. Use caution where a resident depends on a very quiet aquarium or withdraws from food when surrounded by fast swimmers. Peaceful temperament alone does not settle that decision because activity can cause pressure without direct aggression.

Browse the rasboras and danios collection to compare identities, then assess each animal separately. Where behaviour between two exact species remains uncertain, base the decision on the more demanding water, space and activity requirement.

Answer common buyer questions

How big does a Glowlight Danio get?

A Glowlight Danio reaches 3.1 cm standard length according to FishBase. Standard length excludes the tail, and its active swimming still requires a base of at least 80 × 30 cm.

What size aquarium does a Glowlight Danio need?

Use a covered aquarium with a base of at least 80 × 30 cm and an approximate volume of 72 litres or more. Preserve open swimming room and provide planted or structured margins with calmer areas away from the strongest flow.

How many Glowlight Danios should I keep?

Keep at least eight Glowlight Danios and aim for ten where the aquarium dimensions, filtration and total stocking permit. This is a schooling species and should not be planned as a solitary fish.

Is a Glowlight Danio suitable for beginners?

A Glowlight Danio can suit a prepared beginner who has a mature filtered aquarium, a secure cover, an 80 × 30 cm or larger base and room for at least eight fish. The keeper must test the water and complete regular maintenance.

What does a Glowlight Danio eat?

Feed a Glowlight Danio a good-quality dried staple once a day in an amount eaten within a few minutes. Regularly supplement it with small live or frozen bloodworm, Daphnia or Artemia.

What temperature and pH does it need?

Keep it at 16–26°C, pH 6.0–8.0 and 1–12 dGH. These are the species aquarium values from Seriously Fish; choose stable conditions that also suit every companion.

Is it aggressive or likely to nip fins?

It is generally very peaceful, but its constant activity may stress more timid fish. Plan around its swimming pace, maintain a group of at least eight and investigate persistent chasing, isolation or fin damage.

Which kinds of fish can live with it?

Other small cyprinids, tetras, livebearers, rainbowfish, anabantoids, catfish and loaches are possible after exact checks. Match temperature, pH, hardness, adult space, flow and feeding pace, and use caution with very timid fish.

How does it arrive alive in the UK?

Someone must be present to receive it. Film every delivery continuously from the sealed parcel as it is opened, with the fish still in the sealed bag; float the bag for 20–30 minutes, then release the fish without pouring bag water into the aquarium.

Consult the care references

• FishBase — scientific identity, family, distribution, environment, conservation assessment and maximum recorded standard length.
• Seriously Fish — species aquarium dimensions, water range, layout, filtration, feeding, social behaviour and community guidance.
• OATA — UK group guidance for danio water quality, feeding, introduction, maintenance and health observation.
• RSPCA — general aquarium welfare guidance on biological filtration and toxic nitrogen waste.