Catfish & plecos · Kryptopterus vitreolus

Glass catfish care guide

Also called: Ghost catfish, Phantom catfish, Asian glass catfish, Transparent catfish

The glass catfish is a see-through Thai catfish that schools in midwater instead of hiding on the bottom. It's shy and sensitive, so keep at least 6 in a mature, dimly lit tank of 29 gallons (110 L) or more with calm tankmates.

Glass catfish need a tank of at least 29 gallons (110 L), a group of 6 or more, and water at 23–26°C (73–79°F) with a pH of 6–7. They grow to about 7 cm (2.8 in) and are peaceful.

Plan a tank with glass catfishSee all tank mates

Glass catfish quick facts

Scientific nameKryptopterus vitreolus
FamilySiluridae
OriginPeninsular and southeastern Thailand (nearly all are wild-caught)
Adult size7 cm (2.8 in)
Minimum tank29 gallons (110 L), at least 90 cm (35 in) long
Temperature23–26°C (73–79°F)
pH6–7
Hardness (GH)2–10 dGH
Group size6 or more (schooling fish)
TemperamentPeaceful
Swims atMiddle
DietCarnivore
Care levelModerate
Lifespan5–8 years
Safe with shrimp?Mostly (eats baby shrimp)
Safe with plants?Yes

Tank setup

A group of six needs at least a 29-gallon (110 L) tank about 3 ft (90 cm) long. Use floating plants or dim lighting, with plants and driftwood along the sides and open water in the middle. Keep the current gentle to moderate. Only add them to a fully cycled, mature tank.

How many glass catfish in a tank?

The smallest common tank that suits glass catfish is a 40 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.

TankGlass catfish (alone)
3 gallonToo small
5 gallonToo small
10 gallonToo small
15 gallonToo small
20 gallonToo small
20 gallon longToo small
29 gallonToo small
40 gallon6–23
55 gallon6–32
75 gallon6–44
125 gallon6–73

What you need for glass catfish

Sized for a 29 gallon tank, the smallest common size that suits a group of 6 glass catfish. For a different tank or a mix of fish, use the stocking calculator for a list sized to your plan.

Tank and equipment

Food and extras for glass catfish

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Water parameters

Keep the temperature at 23–26°C (73–79°F), pH 6.0–7.0 and soft to medium water (about 2–10 dGH). They react badly to sudden changes, so match temperature and chemistry closely during water changes and acclimation. Ammonia and nitrite must always read zero.

Best tank mates for glass catfish

These popular species share glass catfish' water needs and temperament. See the full list of 103 good matches.

Avoid keeping glass catfish with

  • Common goldfish: They need different temperatures: Glass catfish 23–26°C (73–79°F), common goldfish 15–22°C (59–72°F).
  • Oscar: Oscar can eat glass catfish: they're small enough to fit in its mouth once it's grown.
  • Chinese algae eater: Chinese algae eater is aggressive and will bully or injure peaceful glass catfish.
  • Convict cichlid: Convict cichlid is aggressive and will bully or injure peaceful glass catfish.
  • Discus: They need different temperatures: Glass catfish 23–26°C (73–79°F), discus 28–30°C (82–86°F).
  • Electric yellow cichlid: Electric yellow cichlid is a Lake Malawi cichlid. It needs a Lake Malawi tank: hard, alkaline water (pH 7.5–8.5), plenty of rockwork and other cichlids from the same lake. Glass catfish don't belong in that setup.

Feeding

In the wild they pick tiny invertebrates out of the water. Many refuse dry food at first, so have frozen or live baby brine shrimp, daphnia and bloodworms ready, then wean them onto micro pellets and crushed flakes that drift in midwater. Feed small amounts once or twice a day, as they rarely chase food to the bottom.

Behavior

Glass catfish are peaceful but timid, and a lone fish or a tiny group will hide and waste away. They hang together in a loose school, usually facing into the current. Good tankmates are small, calm fish such as rasboras, small tetras, kuhli loaches and corydoras. Avoid boisterous or large fish that outcompete them for food.

Breeding

Spawning in home aquariums is rarely reported, and the species is not known to be bred commercially, so nearly all are wild-caught. There is no reliable way to tell males from females. They will eat the eggs and fry of other fish.

Tips from experienced keepers

  • Buy a group of at least 6 at the same time. Single glass catfish hide and often stop eating.
  • A healthy glass catfish is clear. A milky or cloudy body is a warning sign, so test your water.
  • Add floating plants to soften the light. They are calmer and more active in shade.
  • Only add them to a tank that has been running and stable for a few months.
  • Skip fast, pushy eaters like large barbs that grab all the food first.

Frequently asked questions

How many glass catfish should be kept together?

Keep at least 6. They are schooling fish and feel unsafe in smaller groups, which leads to hiding, stress and poor feeding.

Why is my glass catfish turning white?

Healthy glass catfish are almost fully transparent. A cloudy or milky body usually signals stress, poor water quality or illness, so test for ammonia and nitrite right away. Glass catfish also turn opaque white soon after death.

Can glass catfish live with shrimp?

Usually, yes. Adult cherry and amano shrimp are too big for them to eat, but they will pick off tiny baby shrimp, so dense moss helps a shrimp colony keep growing.

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.