Dwarf Neon Rainbowfish
Melanotaenia praecox
Also known as Praecox Rainbowfish
Edited by Ivan F. · Reviewed
Beginner verdict
A compact, electric blue rainbowfish with red-edged fins, perfect for a planted community tank. It is very peaceful and suits many small fish, but it can be skittish unless kept in a proper shoal. Keep several and the males will show off their brightest colors daily.
Care at a glance
- Min tank size
- 14 US gal
- Footprint
- 24 x 12 in
- Temperature
- 73–82 °F
- pH
- 6.8–7.5
- Hardness
- 5–15 dGH
- Swim zone
- Mid-Water
- Min group
- 6 or more
- Lifespan
- 3–4 years
Dwarf Neon Rainbowfish tank mates and swim zone
Mid-Water
Spends most of its time in this part of the tank.
Poecilia reticulata
Xiphophorus maculatus
Xiphophorus hellerii
Poecilia sphenops
Trichogaster chuna
Trichogaster lalius
Hyphessobrycon amandae
Dwarf Neon Rainbowfish is much larger than Ember Tetra and may frighten or even eat it.
Boraras brigittae
Dwarf Neon Rainbowfish is much larger than Chili Rasbora and may frighten or even eat it.
Danio margaritatus
Dwarf Neon Rainbowfish is much larger than Celestial Pearl Danio and may frighten or even eat it.
Barbodes semifasciolatus
Their temperature ranges barely overlap, so you will have little room for error.
Tanichthys albonubes
Their temperature ranges do not overlap, so one of them would always be stressed.
Carassius auratus
Goldfish suit cooler water and are not suited to tropical tanks, so Dwarf Neon Rainbowfish is a poor match.
Dwarf Neon Rainbowfish feeding and care
How to feed
- Feed quality flakes and small pellets.
- Add live or frozen foods regularly for its strongest color.
- Feed small portions you can see finished within a couple of minutes, because overfeeding fouls the water fast.
Telling males from females
Mature males are larger and brighter than females, with a much deeper body and red-edged fins.
Dwarf Neon Rainbowfish care mistakes to avoid
- Do not buy just one or two. Keep at least 6 fish so they feel secure.
- Keep a real shoal. A few fish stay skittish and rarely display their color.
- Use a lid, because startled rainbowfish can jump.
- Give it open swimming room at the front, even in a heavily planted tank.
- Check your tank before you buy. Our sourced minimum is 14 US gallons.
Dwarf Neon Rainbowfish tank setup
A forgiving setup with room for a small community.
TankAt least 14 US gal (54 L), 60 x 30 cm
The smallest tank our sources give for Dwarf Neon Rainbowfish. We list only tanks that hold this volume (allowing 10%, so a standard size counts) and have at least this much floor.
Aqueon Standard Glass Aquarium 20 Long US
Aqueon Standard Glass Aquarium 29 Gallon US
Eheim clearTank 73 Spain
Why we chose these (Best 20-Gallon Fish Tank: 20 Long or 29?). Nobody here has used or tested them.
Starter kitA kit with the tank, filter and light in one box
We list only kits whose tank fits Dwarf Neon Rainbowfish, up to twice its minimum volume. A kit whose heater has a fixed setting shows only when that setting is inside Dwarf Neon Rainbowfish's temperature range.
Tetra Complete LED Aquarium Kit 20 Gallon US
Check the heater's setting
Tetra Starter Line LED Aquarium 54 L Spain
Heater preset to 25 °C
Tetra Starter Line LED Aquarium 80 L Spain
Heater preset to 25 °C
Why we chose these (Best Aquarium Starter Kit: What to Look For). Nobody here has used or tested them.
FilterHang-on-back or large sponge filter
Easy to maintain and strong enough for a community without blasting the fish.
Seachem Tidal 55 Power Filter US
Marineland Penguin PRO 175 Power Filter US
Eheim LiBERTY 130 Hang-on Filter Spain
Seachem Tidal 35 Power Filter Spain
Why we chose these (Best Filter for a 20 to 29-Gallon Tank). Nobody here has used or tested them.
HeaterKeep it at 73–82 °F (23–28 °C)
Adjustable heater, about 5 W per gallon: 100 W at 20 gallons, about 150 W at 29. Enough power to hold a stable temperature in most homes. Size up for a cold room.
Aqueon Pro Adjustable Heater 100 W US
Aqueon Submersible Glass Heater 100 W US
Eheim Thermocontrol e 100 Heater Spain
Tetra HT 100 Electronic Heater Spain
Why we chose these (Best Heater for a 20 to 29-Gallon Tank). Nobody here has used or tested them.
Water conditionerDechlorinator such as Seachem Prime
Tap water contains chlorine or chloramine that harms fish.
Seachem Prime US
Fritz Complete Water Conditioner US
API Betta Water Conditioner US
sera aquatan Spain
Tetra AquaSafe Spain
Sold at Kiwoko · Sold at Tiendanimal · Sold at zooplus.es · Maker's details
Why we chose these (Best Water Conditioner for Betta Fish). Nobody here has used or tested them.
Test kitLiquid kit such as API Freshwater Master
Tracks ammonia, nitrite, nitrate and pH while the tank cycles.
API Freshwater Master Test Kit US
API General & Carbonate Hardness Test Kit US
See it at The Shrimp Farm (a retailer; affiliate link) · Sold at Bulk Reef Supply · Maker's details
sera aqua-test box (Cl) Spain
JBL PROAQUATEST COMBISET Plus NH4 Spain
Why we chose these (Best Test Kit for a Freshwater Aquarium). Nobody here has used or tested them.
SubstrateAny substrate
We are still choosing products for this.
Hiding places and decorIdeally suited to a heavily planted setup with floating plants to dim the light and open swimming space.
We are still choosing products for this.
PlantsSafe with live plants
Cycle the tank before adding animals. See our guide on how to cycle a fish tank.
Where to buy Dwarf Neon Rainbowfish
We have not found a store that sells Dwarf Neon Rainbowfish under its scientific name yet. We add stores as we confirm them.
Live animals and plants travel by courier. Check the store's live-arrival guarantee, and only buy once your tank has cycled (see how to cycle a fish tank).
Some US states restrict certain species. Check our US state aquarium rules table and your state's own rules before you buy.
Dwarf Neon Rainbowfish FAQ
What size tank do Dwarf Neon Rainbowfish need?
Our sourced minimum is 14 US gallons (54 liters), with a footprint of 60 x 30 cm. A bigger tank is always easier to keep stable.
How many Dwarf Neon Rainbowfish should I keep?
Keep at least 6 fish. Bigger groups usually look better and behave more confidently.
What can live with Dwarf Neon Rainbowfish?
Good matches on our list include Fancy Guppy, Platy and Swordtail. Avoid White Cloud Mountain Minnow and Goldfish.
How long do Dwarf Neon Rainbowfish live?
Care guides report about 3–4 years. Stable water and a good diet make the biggest difference.
How can I tell male and female dwarf neon rainbowfish apart?
Males have red or orange edges on their fins and a deeper body. Females have yellow-orange fins and look slimmer and plainer.
Dwarf Neon Rainbowfish facts and sources
- Family
- Melanotaeniidae
- Native to
- Mamberamo River, West Papua
- Adult size
- 3.1 in (8 cm)
- Temperament
- Peaceful
- Social needs
- Schooling/Shoaling (6+)
- Diet
- Omnivore
- Water flow
- Moderate
- Substrate
- Any
- Live plants
- Yes - Loves Plants
- Shrimp
- Adult Shrimp Only
- Fin nipping
- None
- Vulnerable to nippers
- No
- Breeding
- Moderate
Sources
- Seriously Fish: Tank size, water ranges and behavior
- FishBase: Cross-check of water ranges and size
Lifespans are approximate and come from aquarium care guides, because these databases rarely publish them.
Where sources differ, we show the Seriously Fish aquarium figures.
Spotted something wrong? Report a parameter correction. For a sick fish, see our veterinary disclaimer.