Best Rainbowfish for Beginners: Hardy, Colorful Fish That Get Better With Age

Rainbowfish are some of the most rewarding fish a new hobbyist can keep. They’re hardy, active, peaceful, and they get more colorful the longer you own them — a male Boesemani Rainbowfish (Melanotaenia boesemani) that looks plain at the store can develop vivid iridescent colors, with blue and orange tones once it settles into a stable tank. This guide rounds up the best rainbowfish for beginners, what makes each one easy to care for, and how to set them up for success here in Cheyenne.

What makes rainbowfish great beginner fish?

Many commonly kept rainbowfish are surprisingly hardy, but beginners should still choose species that match their aquarium size and water conditions. Members of the Melanotaeniidae family are well known for their active schooling behavior, iridescent scales, and vibrant appearance. Most larger rainbowfish are relatively beginner-friendly, while delicate threadfins may need more experience. Most rainbowfish are forgiving of the things that trip up new aquarists. They tolerate a wide pH and hardness range, handle the firm, mineral-rich water that comes out of most Cheyenne taps, and aren’t fussy eaters. They’re also schooling fish, so keeping a group of six or more brings out their best color and most natural behavior. If you want the full background on the family, start with our complete rainbowfish care guide.

The best rainbowfish for beginners

Here are our top picks, from full-size showpieces to peaceful nano species. The boesemani rainbow fish is a colorful option for a roomy community aquarium; smaller blue-eye species often display bright blue eyes and delicate fins:

• Boesemani Rainbowfish – the classic. Half blue, half orange, hardy, and stunning in a group. Our favorite first rainbowfish — see the dedicated boesemani care guide.
• Turquoise Rainbowfish – shimmering blue-green and just as easygoing; details in the turquoise care guide.
• Dwarf Neon Rainbowfish – electric blue with red fins, tops out around 2 inches, perfect for smaller tanks.
• Paskai Red Neon Rainbowfish – a striking red-and-blue variant that stays compact and colorful.
• Threadfin Rainbowfish – delicate trailing fins and a peaceful nature; great for planted nano tanks. More in the threadfin care guide.
• Forktail (Furcata) Rainbowfish – a tiny, active blue-eye rainbow with yellow-edged fins, ideal for nano aquascapes.

Looking for the dwarf, peaceful end of the family? The Gertrudae (spotted blue-eye) care guide is worth a read too.

How many should you keep?

Rainbowfish thrive in groups, and their social schooling behavior is part of what makes them entertaining. Aim for at least six of a compatible species so males can display and develop richer color. Their peaceful temperament makes many species suitable as peaceful community fish, provided tank mates share similar water needs. Larger species like boesemani and turquoise reach 3–4 inches and appreciate a tank of 30 gallons or more, while the nano species (threadfin, forktail, dwarf neon) are happy in well-planted tanks of 15–20 gallons. Need stocking ideas around a rainbowfish school? See our best fish for a 55 gallon tank guide.

Water and tank setup

Many popular larger rainbowfish appreciate moderately hard, neutral to slightly alkaline water, which can make them a good fit for Cheyenne. However, water chemistry requirements vary, and some smaller species come from softer water; check the needs of each fish rather than assuming they all prefer hard water. If you’re unsure about your parameters, check our breakdown of how hard Cheyenne tap water is for aquariums, and our roundup of the best freshwater fish for hard water. Aim for well-oxygenated water, a securely covered aquarium, and dependable filtration without turbulent flow throughout the tank. Aquatic plants along the sides, floating plants for shaded areas, and open swimming room make attractive planted aquariums and help shy fish feel secure. Give them open swimming space up front and plant the back and sides — they show off beautifully in a planted layout, so our best fish for a planted aquarium guide pairs well here.

Feeding for maximum color

Rainbowfish are generally omnivores that color up best on a varied diet. Rotate quality flakes or appropriately sized pellets with small live foods and frozen foods such as brine shrimp, daphnia, and bloodworms when suitable for the species. Cleanly cultured mosquito larvae can also be an occasional live-food option, but never collect larvae from pesticide-contaminated water. Different fish have different mouth sizes, so feed appropriately sized portions. A good staple flake at every feeding keeps the whole school active and bright.

Choosing Rainbowfish for Community Tanks

A peaceful community fish still needs compatible tank mates. Mid-sized rainbowfish generally suit similarly active community fish in spacious tanks, while tiny threadfin and blue-eye rainbowfish are best with gentle neighbors that will not outcompete them at feeding time. Rainbowfish usually do well in a well-planted community aquarium, but watch for chasing and fin nipping when selecting companions. Choose stocking levels based on adult size, swimming room, and filtration rather than appearance alone.

Rainbowfish Colors and Natural Behavior

Rainbowfish often show the strongest iridescent colors as they mature, particularly when kept in groups with both sexes and given stable conditions. The shimmering scales of Melanotaenia boesemani become especially striking in adult males, while many Pseudomugil blue-eyes display blue eyes and colorful fins. Not every species colors up equally under the same lighting; good nutrition and low stress support their natural appearance.

Rainbowfish Breeding Basics

Many rainbowfish are egg scatterers that deposit adhesive eggs among fine-leaved plants or spawning mops. Healthy adults may spawn repeatedly, but eggs and fry can be eaten in a shared tank. For breeding projects, use a separate setup, monitor egg development, and provide fry-sized foods. Breeding success and preferred water parameters vary widely between species.

Beginner Rainbowfish Questions

Are rainbowfish good for planted aquariums?

Yes. Most popular rainbowfish leave healthy plants alone. Provide dense greenery along the edges and plenty of open space for active swimming.

Can rainbowfish live with other community fish?

Many can, thanks to their generally peaceful nature. Match companions by adult size, activity, temperature, and temperament; delicate nano rainbowfish need especially gentle tank mates.

What do rainbowfish eat?

Offer a varied staple of good-quality flake or small pellets with occasional suitable live and frozen foods, including daphnia and brine shrimp. Avoid overfeeding.

Shop rainbowfish

Browse our full rainbowfish collection to explore species and check current availability. Live fish are available for in-store purchase or local pickup only.

The bottom line

If you want a fish that’s hardy, peaceful, and only gets more beautiful with time, rainbowfish are hard to beat for a first “wow” species. Start with a school of six boesemani or dwarf neons, give them stable water and a varied diet, and you’ll have a living rainbow in no time.