Boesemani rainbowfish care guide
Also called: Boeseman's rainbowfish, Boesemani rainbow, Bosemani rainbowfish
Boesemani rainbowfish are active schooling fish whose males turn bright blue at the front and orange-yellow at the back. Keep six or more in a long tank, at least 4 ft (120 cm), with hard, alkaline water and a tight lid.
Boesemani rainbowfish need a tank of at least 29 gallons (110 L), a group of 6 or more, and water at 26–29°C (79–84°F) with a pH of 7–8. They grow to about 10 cm (3.9 in) and are peaceful.
Plan a tank with boesemani rainbowfishSee all tank mates
Boesemani rainbowfish quick facts
| Scientific name | Melanotaenia boesemani |
|---|---|
| Family | Melanotaeniidae |
| Origin | Ajamaru (Ayamaru) Lakes, Bird's Head Peninsula, West Papua, Indonesia (endangered in the wild; aquarium fish are mostly captive-bred) |
| Adult size | 10 cm (3.9 in) |
| Minimum tank | 29 gallons (110 L), at least 120 cm (47 in) long |
| Temperature | 26–29°C (79–84°F) |
| pH | 7–8 |
| Hardness (GH) | 10–20 dGH |
| Group size | 6 or more (shoaling fish) |
| Temperament | Peaceful |
| Swims at | Middle |
| Diet | Omnivore |
| Care level | Easy |
| Lifespan | 5–8 years |
| Safe with shrimp? | No, eats shrimp |
| Safe with plants? | Yes |
- Known jumper: keep a tight-fitting lid.
Tank setup
A group of six needs at least 29 gallons (110 L) in a tank 4 ft (120 cm) long, and a bigger group needs more. Plant the back and sides but leave a long open lane, because these fish swim the full length of the tank all day. Fit a tight lid, since rainbowfish can jump when startled.
How many boesemani rainbowfish in a tank?
The smallest common tank that suits boesemani rainbowfish is a 55 gallon. Here is roughly how many fit in each size when they are the only fish, based on adult size and waste output. Leave room if you want tank mates.
| Tank | Boesemani rainbowfish (alone) |
|---|---|
| 3 gallon | Too small |
| 5 gallon | Too small |
| 10 gallon | Too small |
| 15 gallon | Too small |
| 20 gallon | Too small |
| 20 gallon long | Too small |
| 29 gallon | Too small |
| 40 gallon | Too small |
| 55 gallon | 6–15 |
| 75 gallon | 6–21 |
| 125 gallon | 6–35 |
What you need for boesemani rainbowfish
Sized for a 29 gallon tank, the smallest common size that suits a group of 6 boesemani rainbowfish. For a different tank or a mix of fish, use the stocking calculator for a list sized to your plan.
Tank and equipment
- 29 gallon aquarium (tank or kit) (opens Amazon in a new tab)Bigger tanks are more stable and easier for beginners. How to choose
- Aquarium stand for 29 gallons (opens Amazon in a new tab)The water alone weighs about 242 lb (110 kg), before glass, gravel and rock. How to choose
- Adjustable heater, 150 W (opens Amazon in a new tab)Holds about 82 °F (27.5 °C) in a room at 65 °F (18 °C). How to choose
- Aquarium thermometer (opens Amazon in a new tab)Check it daily: heaters can fail stuck on or off. How to choose
- Hang-on-back filter rated 115–175 GPH (opens Amazon in a new tab)Community tank: 4–6 times the tank volume per hour. How to choose
- About 45 lb of aquarium gravel (opens Amazon in a new tab)Enough for a layer about 2 in (5 cm) deep. Smooth gravel suits most community fish. How to choose
- Water conditioner (dechlorinator) (opens Amazon in a new tab)Removes chlorine and chloramine from tap water. Seachem Prime is a popular, concentrated choice. How to choose
- Liquid test kit (ammonia, nitrite, nitrate, pH) (opens Amazon in a new tab)Liquid kits are more accurate than strips. The API Freshwater Master Test Kit is the common choice. How to choose
- Gravel vacuum (siphon) (opens Amazon in a new tab)Cleans the gravel and does the water change in one go. How to choose
- LED aquarium light, about 30 in long (opens Amazon in a new tab)Match the light to the tank length. Basic LEDs grow easy plants. How to choose
Food and extras for boesemani rainbowfish
- Tropical fish pellets (opens Amazon in a new tab)A good staple for medium community fish.
- Tight-fitting lid for a 29 gallon tank (opens Amazon in a new tab)Boesemani rainbowfish can jump out of an open tank.
Product links go to Amazon search results. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you. Disclosure.
Water parameters
Keep it warm at 26–29 °C (79–84 °F), with pH 7.0–8.0 and 10–20 dGH. Avoid running it hotter for long periods, which can shorten its life. It does poorly in soft, acidic water, so add crushed coral if your tap water is soft. Moderate flow and weekly water changes keep it healthy and colorful.
Best tank mates for boesemani rainbowfish
These popular species share boesemani rainbowfish' water needs and temperament. See the full list of 37 good matches.
Betta fish
6.5 cm (2.6 in) · 24–28°C (75–82°F)
Dwarf gourami
7.5 cm (3 in) · 24–28°C (75–82°F)
Angelfish
15 cm (5.9 in) · 24–29°C (75–84°F)
Ember tetra
2 cm (0.8 in) · 23–28°C (73–82°F)
Cardinal tetra
4 cm (1.6 in) · 23–28°C (73–82°F)
Glowlight tetra
4 cm (1.6 in) · 24–28°C (75–82°F)
X-ray tetra
4.5 cm (1.8 in) · 24–28°C (75–82°F)
German blue ram
6 cm (2.4 in) · 27–30°C (81–86°F)
Avoid keeping boesemani rainbowfish with
- Cherry shrimp: Boesemani rainbowfish eats small shrimp like cherry shrimp.
- Common goldfish: They need different temperatures: Boesemani rainbowfish 26–29°C (79–84°F), common goldfish 15–22°C (59–72°F).
- Fancy goldfish: They need different temperatures: Boesemani rainbowfish 26–29°C (79–84°F), fancy goldfish 18–23°C (64–73°F).
- Neon tetra: They need different temperatures: Boesemani rainbowfish 26–29°C (79–84°F), neon tetra 21–25°C (70–77°F).
- Oscar: Oscar can eat boesemani rainbowfish: they're small enough to fit in its mouth once it's grown.
- Panda corydoras: They need different temperatures: Boesemani rainbowfish 26–29°C (79–84°F), panda corydoras 21–25°C (70–77°F).
Feeding
This omnivore eats almost anything. Feed a quality flake or small pellet daily, and add frozen or live bloodworms, daphnia and brine shrimp a few times a week. Some spirulina or other plant-based food rounds out the diet, and variety gives the best color.
Behavior
It is peaceful toward other fish, but fast and busy, which can stress slow or shy species. Good tank mates are similar-sized barbs, danios, larger tetras, other rainbowfish, corydoras and loaches. Males display and chase each other but rarely do harm, so keep more females than males. Adults will eat cherry shrimp.
Breeding
Males are larger, deeper-bodied and brighter, and show a pale stripe on the forehead when ready to spawn. Pairs scatter a few eggs each day over fine-leaved plants or a spawning mop for weeks. Move the mop to another tank, where eggs hatch in about 7–12 days. Fry are tiny and need infusoria or powdered fry food first, then baby brine shrimp.
Tips from experienced keepers
- Shop fish often look dull grey. Full adult color can take up to a year to develop.
- Keep more females than males so males show their best colors and no single fish gets chased all the time.
- Choose a long tank over a tall one: these fish cruise the full length of the tank.
- Feed live or frozen food at least weekly to keep the blue and orange strong.
- Skip cherry shrimp. Adult boesemani will hunt them.
Frequently asked questions
How many boesemani rainbowfish should be kept together?
Keep at least six, and more if your tank allows. A mixed group with more females than males gives the best color and the calmest behavior.
How big do boesemani rainbowfish get?
Males usually reach about 4 in (10 cm) and can grow to 4.5 in (11 cm). Females stay smaller, around 3 in (8 cm).
Why is my boesemani rainbowfish not colorful?
Young fish, females and stressed fish are pale. Give them time to mature, a varied diet with frozen foods, hard alkaline water and a group with females for the males to display to.
Sources
We checked these references when writing this page. Values are for healthy long-term keeping, not survival limits. Last reviewed 2026-10-13. See our editorial policy.