10 × Lemon Tetras (Hyphessobrycon pulchripinnis)

Choose a social shoal for a peaceful community aquarium

This is a pack of 10 Lemon Tetras, Hyphessobrycon pulchripinnis. One purchase supplies 10 fish, giving you the species group recommended for its social behaviour rather than leaving you to build a shoal one fish at a time.

What to expect from the group

Lemon Tetras are peaceful freshwater fish with a relatively deep body, translucent lemon colouring, a red upper iris and dark edging on the dorsal and anal fins. FishBase lists this species as an American tetra from the Tapajós River basin in South America. Its wild diet includes worms, crustaceans and plant matter, while its aquarium guidance calls for groups of at least five.

A pack of 10 meets the more specific recommendation of maintaining at least 8–10 together. Within a settled group, the fish may form temporary social hierarchies, and males may display to one another while competing for female attention. This behaviour can bring more movement and colour to the aquarium without changing the species’ peaceful community character.

This offer supplies the 10 fish as one pack. Sex is guaranteed only when the selected option explicitly states male or female. This 10 × Lemon Tetras listing has no sex-guaranteed option.

The gallery images are representative of this type of animal rather than photographs of the exact animal supplied, so colours can look slightly different from the live animal.

Plan the aquarium around adult size and swimming room

One purchase supplies a pack of 10 fish. Aquarium planning should use mature dimensions, not the size of the fish at delivery. FishBase gives a maximum of 3.8 cm standard length, while the Seriously Fish species profile uses 40 mm standard length for aquarium planning. Allow around 4 cm per adult before assessing the footprint, filter and other livestock.

Use footprint before volume alone

An aquarium with a base of at least 80 × 30 cm, or an equivalent footprint, should be the smallest considered. That example holds around 72 litres, but the horizontal dimensions matter because all 10 fish need room to swim, regroup and perform social displays. A taller aquarium with a much shorter base may hold a similar volume while offering less usable swimming length.

Use planting and décor to divide the aquarium visually without filling the central swimming route. The species can be kept in a heavily planted layout or over sand with driftwood roots and branches. Both approaches work when the group has cover near the edges and an open route through the middle.

Check the decisive numbers

• Adult length: plan around approximately 4 cm standard length.
• Group: keep all 10 together; at least 8–10 supports the species’ social displays.
• Base: at least 80 × 30 cm or an equivalent footprint.
• Volume: around 72 litres is the smallest species-specific planning reference.
• Routine water: 22–27°C, pH 6.5–7.5 and 4–12 dGH.

Those figures are starting points for a Lemon Tetra aquarium, not permission to fill every remaining space with other fish. Décor, filter capacity, the adult dimensions of companions and the amount of open swimming room all affect the final stocking decision.

This pack suits a keeper who can prepare the full aquarium before the group arrives, maintain stable water and assess companions by adult size and temperament. A newly filled tank, a short nano footprint or a community containing predators should be addressed before choosing the fish.

Set a stable routine water range

Keep the aquarium at 22–27°C, pH 6.5–7.5 and 4–12 dGH. These routine values are the overlap of the wider 20–28°C, pH 5.0–7.5 and 1–12 dGH species limits from Seriously Fish and OATA’s tetra group guidance.

Choose values your aquarium can hold consistently rather than moving pH or hardness repeatedly. Measure the tap water after conditioning, compare it with the aquarium and decide whether the intended routine falls within the range. Our water chemistry guide explains what the common measurements mean, while the water matcher helps compare your measured values with this plan.

Use a simple testing sequence

1. Measure temperature, pH and general hardness before adding the group.
2. Confirm ammonia and nitrite are both zero mg per litre.
3. Use the same tests weekly so a change is visible before fish behaviour is affected.
4. Investigate a changed result before trying to alter several values at once.

If ammonia or nitrite appears, pause further livestock additions, reduce avoidable waste and check the biological filter. A pH or hardness result outside the intended range calls for a measured plan based on both tap and aquarium water, not a sudden chemical swing. Stability must sit alongside suitable values.

Build biological filtration before adding the group

A mature biological filter is essential because 10 fish add waste as a group. The RSPCA’s general aquarium welfare guidance explains that fish release toxic ammonia, which filter bacteria convert first to nitrite and then to the safer nitrate. Both ammonia and nitrite must read zero before the Lemon Tetras enter the aquarium.

For an aquarium of around 72 litres, Seriously Fish uses a turnover of four to five times the tank volume each hour and gives a filter planning range of 290–360 litres per hour. Treat the manufacturer’s flow rating as a starting point: filter media, pipework and accumulated debris can affect the working flow.

Prepare the filter in the right order

• Install the filter before livestock enters the aquarium.
• Mature its biological media and confirm zero ammonia and nitrite with tests.
• Arrange the outlet so the fish retain an open swimming route rather than being pushed constantly into one corner.
• Check intakes and outlets for blockages during weekly maintenance.
• Rinse dirty media lightly in removed aquarium water; do not run it under the tap.

The heater also needs to hold the chosen temperature across the whole aquarium. For a roughly 72-litre tank in a room around 20°C, the species profile uses 50–75 W as a planning reference. Room temperature, aquarium shape and heat loss affect the final requirement, so confirm the actual water temperature with a thermometer rather than relying only on the heater setting.

Read test results as filter feedback

Zero ammonia and nitrite show that the filter is coping at the moment tested. A later reading above zero means the waste load is exceeding current biological processing or the filter has been disrupted. Check for excess food, blocked flow, recently disturbed media or rapid stocking changes. Correct the cause while continuing to monitor the fish.

Preserving established bacteria helps the aquarium process the waste produced by the full shoal and reduces the risk of an abrupt ammonia or nitrite rise.

Arrange cover without losing open swimming space

Build the layout around two needs: shelter at the edges and an unobstructed route for 10 fish to move through the aquarium. A heavily planted arrangement suits Lemon Tetras, as does a natural-looking layout with sand, driftwood roots and branches. Plants or suitable ornaments should provide cover, but the shoal also needs visible open water.

Choose one of two practical layouts

Dried leaf litter may be added to strengthen the natural appearance and provide extra cover. As leaves decompose, microbial colonies develop and can become an additional food source for adults and fry. Decaying leaves also release humic substances considered beneficial in this type of arrangement. Account for all decomposing material in maintenance and water-quality checks.

Substrate can be aquarium sand or gravel. Choose a product intended for aquarium use and place hard décor securely so routine siphoning cannot destabilise it. Any branch, root, ornament or plant pot should leave the fish with clear routes rather than narrow traps.

Check the layout from the fish’s route

1. Look along the 80 cm minimum length and identify one continuous swimming lane.
2. Confirm the shoal can move behind or around cover without entering dead ends.
3. Keep access to the filter intake, outlet and heater clear.
4. Leave enough exposed substrate to remove settled waste during a water change.
5. Reassess swimming room as plants grow rather than treating the first layout as permanent.

Cover supports confidence, while open water permits regrouping and social display. Filling the aquarium densely from front to back may create shelter but reduce the very footprint for which the tank was chosen. Keep both functions in balance.

Feed a small varied portion once a day

Feed once a day and offer only what the group can finish within a few minutes. A good-quality flake or small granule can form the regular aquarium diet. Add suitably small live or frozen foods such as daphnia, small bloodworm or tubifex to provide variety.

The wild fish eats worms, crustaceans and plant matter according to FishBase. Seriously Fish describes a broader natural menu of small invertebrates, crustacea, filamentous algae and fallen fruit. In the aquarium, that omnivorous biology is best met through variety rather than relying permanently on one dried food.

Match food to the fish

• Choose flakes or granules small enough to be swallowed without repeated spitting.
• Distribute the portion so all 10 fish have a chance to feed.
• Use small live or frozen items as part of the varied menu.
• Stop adding food when the group is no longer taking it promptly.
• Remove avoidable leftovers rather than allowing them to decay.

Overfeeding adds decomposing material and can drive harmful waste upwards. Portion control therefore protects both body condition and water quality. The correct amount is the amount the whole group consumes within a few minutes, not a fixed pinch that ignores appetite or food size.

When changing foods, introduce the new item as part of the established varied menu and watch whether every fish can take it. Feeding response is also a useful daily observation point: a sudden reduction can be an early sign that water quality, social pressure or health has changed.

Prepare the aquarium before the pack arrives

Prepare and mature the aquarium before bringing home the group. Our first tropical aquarium guide covers the preparation sequence. The practical endpoint is a stable, heated aquarium with an established filter, suitable pH and hardness, and zero ammonia and nitrite.

A pack of 10 creates one meaningful increase in biological load. Size the filter and complete the maturation work for the whole group before arrival rather than expecting a new filter to catch up after feeding begins. Avoid adding further livestock at the same time, because beneficial bacteria must respond whenever fish numbers and feeding increase.

Follow the arrival sequence

1. Arrange for someone to receive the live-fish parcel so it is not left unattended.
2. Start filming before the sealed parcel is opened, with the outer box visible.
3. Open the parcel in one continuous take and film the fish while they remain inside the sealed bag.
4. Float the bag in the aquarium for 20–30 minutes.
5. Release the fish without pouring transport water into the aquarium.

These steps follow our current delivery and Live Arrival Guarantee policy. Read that policy before the delivery date for the current receiving instructions and any claim requirements.

Use the first day for quiet observation

Count all 10 fish visually once they have entered the aquarium, then check swimming position, breathing, colour and whether the group can use both cover and open water. Transport can change behaviour or colour temporarily, so compare the direction of change over the settling period rather than judging one brief moment.

Do not respond to nervous swimming by adding more fish or making several water changes without testing. Confirm temperature, ammonia and nitrite first. If the values are correct, reduce disturbance and allow the group to explore its prepared cover. If a test is outside the plan, address the water-quality cause promptly.

The arrival routine is easier when the aquarium equipment, test kits, conditioner and maintenance tools are ready beforehand. Preparation keeps the first day focused on the animals rather than last-minute changes to the environment.

Use a repeatable weekly maintenance routine

Change 25% of the aquarium water at least once every week. Treat replacement tap water with a suitable conditioner before it enters the aquarium so chlorine or chloramine cannot damage the fish or the filter bacteria. Use a siphon to remove settled solid waste from accessible areas of the substrate.

Complete the work in a consistent order

1. Test ammonia, nitrite and the other values you routinely monitor.
2. Inspect the fish before moving equipment or décor.
3. Remove approximately 25% of the water while siphoning visible waste.
4. Set aside some removed aquarium water if filter media needs rinsing.
5. Condition the replacement water and return it without causing an abrupt disturbance.
6. Check the filter flow, heater operation and final temperature.

Test at least weekly even when the fish look settled. Ammonia and nitrite must remain at zero, while nitrate should not rise more than 20 mg per litre above its normal tap-water level. A written sequence of results makes gradual changes easier to recognise than relying on memory.

Clean the filter without stripping its biology

Check for blocked intakes, reduced outlet flow or debris around the media. When cleaning is necessary, rinse the media lightly in water removed from the aquarium. Do not run it under the tap because any chlorine or chloramine present may kill the beneficial bacterial population.

A larger aquarium is generally more stable than a very small one, but volume does not replace maintenance. The 80 × 30 cm planning footprint gives the shoal room to move; the weekly routine protects the water in which that movement takes place.

Respond early when behaviour or appearance changes

Learn the group’s normal pattern after it settles. Lemon Tetras may spread out when relaxed and regroup as the situation changes. Adult males tend to be slightly smaller, less deep-bodied and more intensely coloured than females, particularly around the dorsal and anal fins, but appearance does not create a sex guarantee for this pack.

Watch the same signs each day

• Swimming: note hanging at the surface, sitting on the bottom or erratic movement.
• Colour: look for an unusual darker or paler appearance.
• Temperament: notice increased hiding or an unexpected change in aggression.
• Breathing: compare gill-cover movement with the group’s normal rate.
• Appearance: look for white spots, fluffy growths, lost fins, missing scales, bumps or ulceration.
• Condition: check for an increase or decrease in body weight.
• Feeding: notice reduced intake or a loss of interest in food.

When one of these signs appears, test temperature, ammonia, nitrite, pH and the values relevant to your routine before changing several things at once. Check the filter flow, recent feeding and maintenance history at the same time. This separates an environmental problem from a change affecting only one fish.

Do not combine medications or alter temperature as a guess. If the signs continue after immediate water and equipment checks, contact us for health guidance. Clear observations, recent test results and the timing of the change make the next decision more useful.

Screen every tank mate by size, temperament and water needs

Lemon Tetras are described as very peaceful and suit a well-researched community aquarium. The safest companions are similarly sized, peaceful fish whose adult water requirements overlap 22–27°C, pH 6.5–7.5 and 4–12 dGH. Shared temperature alone is not enough: body size, feeding behaviour, swimming space and temperament all matter.

Apply three checks before combining fish

1. Adult size: avoid any fish large enough to eat a Lemon Tetra.
2. Temperament: choose peaceful companions that will not dominate the shoal or feeding area.
3. Water range: confirm that both animals can live within the same stable routine values.

Seriously Fish suggests similarly sized characids, hatchetfish relatives, pencilfish relatives, smaller callichthyid or loricariid catfishes and non-predatory small-to-medium cichlids as categories to investigate. These categories are starting points rather than universal approvals. Each proposed species still needs its own adult-size, behaviour and water assessment.

Compatibility remains conditional because aquarium dimensions, group sizes and individual behaviour change the result. For a stocking and compatibility assessment, contact us with the aquarium dimensions, measured water values, filter details and the exact species and numbers already present.

Protect space and feeding access for the whole group

Begin the stocking plan with the 10 Lemon Tetras as one social unit. Reserve an 80 × 30 cm base and around 72 litres as the smallest aquarium plan before accounting for any companions. Adding another species does not reduce the shoal’s need for open water, edge cover or access to food.

Work through the aquarium in this order

1. Plot the adult size of all 10 tetras at around 4 cm standard length.
2. Mark the open swimming route after plants, wood and equipment are in place.
3. Check the adult dimensions and social group requirement of each proposed companion.
4. Confirm every species shares a workable water range.
5. Assess whether the mature filter can process the combined feeding and waste load.
6. Add livestock gradually rather than making several major increases together.

A candidate may be peaceful yet still be a poor fit if it occupies the same limited space, reaches food first at every meal or requires a different temperature. Conversely, a bottom-oriented fish is not automatically suitable merely because it uses another part of the aquarium. Its adult size, social needs and total biological load still count.

Observe the community after every addition. Increased hiding, missed meals, damaged fins, altered breathing or the whole shoal being driven into one area means the plan needs reassessment. Early action protects the group before a repeated interaction affects condition.

Answer the key questions before choosing the pack

What is Hyphessobrycon pulchripinnis?

It is the Lemon Tetra, a peaceful freshwater American tetra from South America. FishBase places it in Acestrorhamphidae and gives a maximum length of 3.8 cm standard length.

How many fish are in the 10 × Lemon Tetras pack?

One purchase supplies 10 fish. Keep the group together because the species is best maintained in a social group of at least 8–10.

How large does the Lemon Tetra grow?

Plan the aquarium around an adult length of approximately 4 cm standard length. FishBase gives a maximum of 3.8 cm standard length, and the species profile uses 40 mm for aquarium planning.

What aquarium does Hyphessobrycon pulchripinnis need?

Use an aquarium with a base of at least 80 × 30 cm or an equivalent footprint, around 72 litres, with a mature filter, edge cover and open swimming space.

Can 10 × Lemon Tetras be kept alone?

Keep them as a group rather than singly. FishBase calls for at least five, while the species profile recommends at least 8–10; this pack supplies 10 fish.

What water conditions should Hyphessobrycon pulchripinnis be kept in?

Maintain 22–27°C, pH 6.5–7.5 and 4–12 dGH, with ammonia and nitrite at zero mg per litre. Keep nitrate up to 20 mg per litre above the normal tap-water level.

What should this fish eat?

Feed a good-quality flake or small granule once a day, giving only what the group finishes within a few minutes. Add small live or frozen foods such as daphnia, small bloodworm or tubifex for variety.

How should it be acclimatised?

Start filming before the sealed parcel is opened, then open it in one continuous take with the fish still inside the sealed bag. Float the bag for 20–30 minutes before releasing the fish, and do not pour transport water into the aquarium. Have someone present to receive the parcel and read the current delivery policy before the delivery date.

Which tank mates suit this fish?

Screen for peaceful, similarly sized fish with overlapping water requirements. Avoid fish large enough to eat it, and assess boisterous candidates for feeding competition and stress before combining them.

Consult the identity and care references

• FishBase: scientific identity, family, distribution, wild biology, environmental range, group guidance and maximum recorded length.
• Seriously Fish: species aquarium footprint, water limits, filtration planning, layout, diet, behaviour and compatibility categories.
• OATA: UK group guidance for tetra water quality, feeding, introduction, maintenance and health observation.
• RSPCA: general aquarium welfare guidance on biological filtration and the processing of fish waste.
• Tropical Fish Co delivery policy: receiving, acclimatisation and current Live Arrival Guarantee requirements.