Freshwater Fish · Danios & Minnows

White Cloud Mountain Minnow

Tanichthys albonubes

Cold-tolerant minnow for unheated tanksBeginner

Lifespan: 3-5 years
Size: 1.2-1.5 in
Social needs: Shoaler; keep 10+ together
Time: Low; daily feeding, weekly water change
Cost: Low
Diet: Omnivore; flakes, micro pellets, frozen foods

Overview

What is this animal?

The white cloud mountain minnow is a small, hardy fish from cool mountain streams near Guangzhou in southern China, marked with a red-and-iridescent stripe.
It is now rare in its native range but breeds readily and thrives in aquariums.

It is one of the few common community fish that needs no heater, tolerating cool room temperatures with ease.
Forgiving and beginner-friendly, it is a good first shoaling fish, though it dislikes prolonged tropical warmth.

Temperament

Peaceful, active and confident, white clouds shoal loosely and look best in good numbers, where males flare their fins at one another harmlessly.
They are too gentle to bother any reasonable tankmate.

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They suit calm, cool-water communities and pair well with other temperate species.
Avoid housing them with warmth-loving tropicals whose needs conflict, or with large fish that may eat them.

A good fit for

Beginners and first aquariums
Unheated, cool-room or temperate setups
Outdoor ponds in mild climates
Peaceful cool-water community tanks

Common mistakes to avoid

Keeping them in warm tropical tanks long term
Keeping too few, dulling colour and behaviour
Open tanks they can jump from
Pairing with warmth-loving or large fish

Enclosure

Minimum 15 gallons, for a group of 10

Cannot be kept alone. The minimum is 10, and the space above is for that group.

A shoal of ten or more needs at least 15 US gallons on a base of about 24 x 12 in, filtered, with no heater required; many keeper guides accept a 10-gallon tank, but Seriously Fish gives the 24 x 12 in base as the minimum.
They thrive at 61-72°F and suffer at sustained tropical temperatures, making them well suited to unheated rooms and some outdoor ponds in mild climates.

They are active swimmers that appreciate length, gentle current and planted edges.
Tolerant of a wide range of water chemistry, they need only a stable, well-cycled tank and a secure lid, as they can jump.

Check your enclosure

Supplies

Setup

Tank and stand
Filter
Thermometer, plus a heater only if the room runs below the species' range
Substrate, plants and decor
Liquid test kit
Dechlorinator and starter supplies

Ongoing

Quality tropical flake or micro-pellet
Frozen daphnia
Frozen brine shrimp
Frozen or freeze-dried bloodworm (chopped fine; whole bloodworm is too large for celestial pearl danios)
Frozen cyclops or baby brine shrimp (for celestial pearl danios)

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Spirulina or vegetable flake
Small feeding spoon for measured pinches
Fine net for removing leftovers

Safe substrate: Fine, smooth sand · Smooth, rounded fine gravel (not for loaches or sand-sifting cichlids; sand is better for corydoras) · Bare bottom (quarantine and grow-out only)

Work out the cost

Care routine

Daily

Check temperature and equipment
Feed
Head-count and look everyone over

Every few days

Top up evaporationevery 3 days

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Weekly

Check the lid
Test the water
Water change and gravel vacuum
Wipe the front glass only

Every few weeks

Trim and thin the plantsevery 2 weeks

Monthly

Check supplies and reagent dates
Replace or recharge chemical media, if you use any (skip it in a blackwater tank)
Rinse the filter media

Health review: Quarterly temperature and stocking review, every 3 months

Tools

Is your enclosure big enough?Check your measurements against the recommended size What will it cost?Setup, monthly and over its whole life, itemised Is this ammonia reading dangerous?Works out the toxic part from your pH and temperature

Care in depth

Diet

Omnivore; flakes, micro pellets, frozen foods

White clouds are easy-going omnivores that feed at the surface and in midwater.
A quality flake or micro-pellet serves as a reliable staple, rotated with frozen or live daphnia, brine shrimp and bloodworm to support their colours.

Feed small amounts once or twice daily, only what is eaten quickly.
They forage actively and rarely refuse food, so measured portions and the occasional fasting day keep the water clean and the fish in good condition.

Health

Signs of good health, and the common problems

Among the hardiest aquarium fish, white clouds suffer few ailments when kept cool and clean.
Most problems, such as ich or fin rot, follow overheating, poor water quality or stress rather than inherent fragility.

Keeping them at tropical temperatures long term shortens their lives and dulls their colour, so avoid heating the tank.
Quarantine new stock, maintain weekly partial water changes, and fit a lid to prevent jumps.

Is this urgent?

6 warning signs and how fast to act, 3 of them right away

In a fish tank the patient is usually the water. Test before you treat: dosing a healthy tank for a disease it does not have makes things worse.

Go now

Any detectable ammonia or nitrite in a stocked tankLarge water change now with dechlorinated, temperature-matched water. Stop feeding. Test again in 12 hours. Both are directly toxic. How toxic the ammonia reading is depends on pH and temperature, so the same number can be harmless or lethal.

Now

Fish gasping at the surface with fast gill movement, or crowding the filter outflowIncrease surface movement now (gently in a betta or gourami tank, without creating a strong current), then test the water. Either the oxygen has crashed or the gills are being chemically burned. Both are hours-scale problems. Bettas, gouramis and corydoras rise to gulp air as part of normal breathing; the warning is constant gulping, fast gill movement, or the whole group hanging at the top.

Now

Sudden deaths, more than one fish in a dayTest ammonia, nitrite, nitrate and temperature before doing anything else. Do not add medication yet. Multiple simultaneous deaths usually point at the water or the equipment rather than a pathogen, so rule those out first.

Now

Today

Flashing: repeatedly scraping against decor or substrateTest the water, then look closely for parasites. Irritation is either chemical or parasitic; the test tells you which before you medicate.

Today

White salt-grain spots over the body and finsBegin the appropriate treatment today and check the temperature. The parasite's life cycle is temperature-driven, and it multiplies with every cycle you wait.

Today

Soon

Clamped fins, hiding, or refusing food for more than two daysTest the water and review recent changes. Usually the earliest visible sign of a parameter drifting.

A few days

Never add a new fish to a tank that is not fully cycled, and never treat blind. A test kit is cheaper than the fish.

This is general guidance for a healthy adult, not a diagnosis. An exotics vet who knows your animal always overrides it, and the time to find one is before you need one.

Bedding and substrate

3 safe, 4 with a caveat, 2 to avoid

Substrate in an aquarium is a filter as much as a floor. Most of the biology lives in and on it.

Safe

Fine, smooth sandCorrect for corydoras, kuhli loaches, eartheaters such as rams and acaras, and anything else that sifts or burrows. Barbels wear away on sharp gravel.

safe

Smooth, rounded fine gravel (not for loaches or sand-sifting cichlids; sand is better for corydoras)Rinse thoroughly before use. Grain size should be too large to swallow and too small to trap food. Kuhli loaches need sand to burrow into and rams and acaras sift mouthfuls of it; bronze and panda corydoras manage on smooth fine gravel, but sterbai corydoras need sand.

safe

Bare bottom (quarantine and grow-out only)Legitimate for quarantine and grow-out tanks. Easy to clean, but it holds far less biological filtration, and it is no long-term home for burrowing loaches or sand-sifters.

safe

With a caveat

Crushed coral or aragoniteDeliberately raises hardness and pH. Correct for rift-lake cichlids, wrong for soft-water species.

with a caveat

Aquasoil for planted tanksExcellent for plants, but most active soils soften the water and pull pH and KH down for months, and many leach ammonia for the first weeks. Right for soft-water species; wrong for hard-water animals (livebearers, rainbowfish, goldfish, and snails, whose shells erode in soft, acidic water) unless you test GH and KH and remineralise. Cycle around it; do not stock into it.

with a caveat

Very deep sand bedsAnaerobic pockets form below about 2 inches in still sand. Either keep it shallow or keep it stirred.

with a caveat

Painted or coated gravelUsually fine, but coatings chip. Test a handful in a jar for a week first.

with a caveat

Never

Sharp or angular gravel with bottom-dwellersWears down barbels and leads to infection in corydoras and loaches.

never

Anything containing metal, limestone of unknown origin, or shells in a soft-water tankSlowly alters chemistry in ways that are hard to diagnose later.

never

This is our general list for freshwater fish. We have not built one specific to Danios & Minnows yet.

Top resources for more info

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