10 Best Coldwater Fish That Don’t Need a Heater

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1. Sunset Variatus Platy

Sunset variatus platy: vibrant colors, hardy and affordable, small size, peaceful with fish and plants, easy to breed, adaptable to various temperatures and pH levels. Perfect addition to any aquarium!

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2. Celestial Pearl Danio

Popular nano fish: Golden-spotted, red-orange fins resembling brook trout. Tolerates pH 6.8-8.0, cooler waters. Shy but stunning when in a school. Perfect for aquascaping!

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3. Rainbow Shiner

Colorful native fish: Rainbow shiner (Notropis chrosomus) from the US. Brilliant purple and pink spangling, prefers cooler waters. Keep in a school of 6+ for stunning display.

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4. Hillstream Loach

Unusual algae eater: Hillstream loach (Sewellia lineolata). Munches on diatoms and algae, resembles a miniature alien stingray. Prefers cooler waters.

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5. Endler’s Livebearer

Hardy and colorful Poecilia wingei (Endler's livebearer) suitable for room temperature tanks. Peaceful, easy to breed, and adds life to your aquarium.

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6. Clown Killifish

Colorful and active Epiplatys annulatus (clown killifish) with blue eyes and rocket-like tails. Ideal for coldwater community tanks, provide a secure lid.

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7. Cherry Shrimp

Colorful and low-maintenance Neocaridina davidi shrimp are perfect for algae control and breeding in your aquarium. Get started with our care guide.

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8. Dojo Loach

The dojo loach, a larger fish with fun behaviors, is perfect for larger coldwater aquariums. Avoid small species and enjoy their scavenging nature.

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9. Barbs

Keep barbs in groups of six or more to minimize aggression. Rosy barbs are quick and peaceful, while gold barbs are more aggressive. Both species need a 29-gallon tank or larger.

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10. White Cloud Mountain Minnow

Tanichthys albonubes, or White Cloud Mountain minnows, are beginner-friendly, hardy fish that thrive in various tank conditions.

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