Red Dwarf Rasbora
Microrasbora rubescens
A stunning but rare nano species endemic to Lake Inle, Myanmar. Unlike most rasboras that prefer soft acidic water, this species strictly requires harder, alkaline water (pH 7.5+) to thrive and display its vibrant orange-red coloration. They are peaceful, active schoolers that must be kept in large groups in planted aquariums.
Red Dwarf Rasbora At a Glance
Red Dwarf Rasbora Tank Requirements
Will Red Dwarf Rasbora fit in your tank?
Care guides tell you what Red Dwarf Rasbora needs, the next question is whether your tank can safely provide it. Test Red Dwarf Rasbora against your tank size, maintenance needs, and the fish you already keep before you buy.
Red Dwarf Rasbora Water Parameters
Red Dwarf Rasbora Temperament & Compatibility
Red Dwarf Rasbora Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Standard
The standard wild-type form. Males will develop intense orange-red coloration as they mature, especially when kept in their preferred hard water parameters and fed a high-quality diet. Females are slightly plumper and paler.
Differs in 1 trait from base species
Also known as: Unsexed, Wild Type
Red Dwarf Rasbora Care Guide Summary
The Red Dwarf Rasbora, scientifically known as Microrasbora rubescens, belongs to the Cyprinids family group. Adults reach a maximum size of approximately 3 cm and have a fusiform body shape with a moderate growth rate. Classified as peaceful, this species primarily occupies the mid-level and surface zones of the aquarium and produces a low level of biological waste.
To thrive, the Red Dwarf Rasbora requires a freshwater only aquarium with a minimum volume of 40 litres and a tank length of at least 45 cm. Water temperature should be maintained between 20°C and 26°C, with a pH range of 7–8.5 and a general hardness of 8–20 dGH. A low water flow is preferred.
The Red Dwarf Rasbora is a rewarding species to keep, provided its core environmental needs are met. The Red Dwarf Rasbora is typically available in one standard form.
Red Dwarf Rasbora Habitat Setup
When setting up an aquarium for the Red Dwarf Rasbora, a low water flow best suits their natural preferences. Because this species occupies the mid-level and surface zones, the aquarium layout should prioritise adequate surface area with floating cover to make them feel secure near the waterline and open swimming space in the centre of the tank for free movement. Useful additions include dense planting to provide cover, break sightlines, and reduce stress.
Red Dwarf Rasbora Compatibility Notes
Classified as peaceful, the Red Dwarf Rasbora is a schooling species that feels most secure in a sizeable group, where natural shoaling behaviour reduces stress and brings out their best colours. Selecting tankmates that favour different water layers from the mid-level and surface zones can help reduce competition and territorial overlap.
Who Red Dwarf Rasbora Is Actually For
Red Dwarf Rasbora is best for a fishkeeper who wants a species that can settle into a calmer community setup and can provide a keeper who can commit to a proper group of at least 8. It makes the most sense for a hobbyist who will actually build around its needs, especially plants.
The most common mistake is buying Red Dwarf Rasbora for looks first and only later discovering how its adult size, behavior, or bioload changes the whole tank plan. Another frequent problem is underestimating its social needs. A token pair or trio often behaves very differently from a real group.
Red Dwarf Rasbora Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Red Dwarf Rasbora.
15 Gallon Standard
20 Gallon High
20 Gallon Long
29 Gallon Standard
30 Gallon Breeder
36 Gallon Bowfront
Show 21 more tank sizes
Frequently Asked Questions About Red Dwarf Rasbora
How big does Red Dwarf Rasbora get?
Red Dwarf Rasbora (Microrasbora rubescens) typically reaches a maximum adult size of approximately 3 cm. They have a fusiform body shape and a moderate growth rate.
What tank size does Red Dwarf Rasbora need?
A minimum aquarium volume of 40 litres and a tank length of at least 45 cm are recommended for Red Dwarf Rasbora. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Red Dwarf Rasbora need?
Red Dwarf Rasbora thrives in freshwater only conditions with a temperature range of 20–26°C, a pH between 7 and 8.5, and a general hardness of 8–20 dGH. A low water flow is preferred.
Is Red Dwarf Rasbora peaceful or aggressive?
Red Dwarf Rasbora is classified as peaceful with an aggression score of 1 out of 10. They are generally well-suited to peaceful community tanks.
How many Red Dwarf Rasbora should be kept together?
Red Dwarf Rasbora is a schooling species and should be kept in groups of at least 8. Larger groups help distribute aggression and encourage natural schooling behaviour.
Does Red Dwarf Rasbora have any special tank requirements?
Yes. Red Dwarf Rasbora benefits from plants - densely covered in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Useful setup supplies
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Guidarium Editorial Desk
Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.
- Last reviewed
- May 11, 2026
- Last updated
- May 11, 2026
- Issues or corrections?
- Contact the editorial team
Top Tank Mates for Red Dwarf Rasbora
These fish are strong compatibility matches for Red Dwarf Rasbora based on water preferences, temperament, adult size, and tank behavior.
Trapdoor Snail
Cipangopaludina chinensis
Ideal Tank MatesGolden Bristlenose Pleco
Ancistrus sp. L144
Ideal Tank MatesMalaysian Trumpet Snail (MTS)
Melanoides tuberculata
Ideal Tank MatesAssassin Snail
Anentome helena
Ideal Tank MatesBristlenose Pleco
Ancistrus cf. cirrhosus
Ideal Tank MatesSnowball Shrimp
Neocaridina cf. zhangjiajiensis var. white
Ideal Tank MatesPlants That Suit Red Dwarf Rasbora
These plants pair well with Red Dwarf Rasbora based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
Amazon Frogbit
Limnobium laevigatum
Asian Watergrass
Hygroryza aristata
Asian Watermoss
Salvinia cucullata
Beckett's Water Trumpet
Cryptocoryne beckettii
Broad-leaved Crypt
Cryptocoryne pontederiifolia
Carolina Fanwort
Cabomba caroliniana
Fish Similar to Red Dwarf Rasbora
Rummynose Rasbora
Sawbwa resplendens
An active, striking nano fish endemic to Inle Lake in Myanmar. Uniquely, they are completely scaleless. They strictly require hard, alkaline water to thrive and are sensitive to medications due to their lack of scales. They are schooling fish that must be kept in groups to feel secure and display their best behavior.
Chili Rasbora
Boraras brigittae
A striking, deeply red nano fish native to the blackwater streams and peat swamps of southern Borneo. They are extremely peaceful and require a mature, densely planted aquarium with soft, acidic water. Due to their tiny size, they are completely safe with adult dwarf shrimp and are ideal for nano setups.
Cherry Spot Rasbora
Rasbora rubrodorsalis
A peaceful and active nano cyprinid native to the slow-moving, heavily vegetated waters of the Mekong basin in Southeast Asia. It is characterized by a distinctive bright red spot on its dorsal fin and a dark lateral line. They are a somewhat shy but excellent shoaling species that thrives in blackwater or heavily planted setups.
Dwarf Rasbora
Boraras maculatus
A tiny, peaceful shoaling fish native to the blackwater streams and peat swamps of Southeast Asia. Known for their striking red/orange coloration and distinct dark body spots. They are an excellent choice for heavily planted nano tanks and peaceful dwarf shrimp setups. Because of their minute size, they are easily outcompeted for food and predated upon by larger fish.
Nana Rasbora
Microdevario nana
A true micro-fish endemic to Myanmar, the Nana Rasbora rarely exceeds 1.5cm (0.6 inches). They exhibit a translucent yellowish body with a subtle iridescent blue lateral stripe and a distinct black blotch on the dorsal fin. Due to their minute size, they are completely peaceful, highly shrimp-safe, and must be kept in schools of at least 6-8 in densely planted, mature aquariums. Providing leaf litter and dim lighting will help them feel secure.
Redline Rasbora
Rasbora pauciperforata
A slender, elegant schooling fish native to the blackwater peat swamps of Southeast Asia. Distinguished by a brilliant, glowing neon-red stripe running from its mouth to its tail. They are true blackwater fish, requiring soft, acidic water and plenty of tannins from leaf litter or driftwood to thrive and show their best colors. Peaceful but can be skittish if not kept in appropriately large schools with overhead cover.