Should I buy it?
Glass Catfish
Kryptopterus vitreolus
Also known as: ghost cat, glass (ghost) catfish
A transparent schooling catfish that needs a group of eight or more to feel safe. Solo or small groups become permanent hiders with visible stress.
Glass Catfish tank mates · 80L tank size hub
peaceful · intermediate care
Sources & confidencehigh · partially verified · beginner: caution
Checked against several solid care sources that mostly agree. Numbers here are a careful starting point. Your tap water, tank size, and habits decide the rest. How we evaluate.
Best for: Mature planted community tanks 80L or more with a school of eight and gentle water flow.
Avoid if: Your tank is under six months old, you can't source eight fish, or you keep nippy mid-water species.
Common mistakeBuying three glass catfish for a busy community is how keepers invent invisible, wasting fish. They need a school of six or more and calm company; under-stocked, they hide behind the filter and fade. Start with numbers and gentle neighbours, not with a novelty trio.
Top things that go wrong
- Group welfare — not a solo display fish. Plan at least **6** together for normal behaviour; smaller groups often mean stress, colour loss, or nipping depending on species.
- Shrimp & snails. Cherry shrimp and other dwarfs can coexist with peaceful small fish; baby shrimp are food for almost anything that finds them.
What most shops don't tell you
- 1.Myth: glass catfish are hardy beginners that thrive alone in bright bare tanks. Reality: they are shy schooling fish that need a tight group, dimmer light, and planted cover before they settle — solo or exposed fish often hide, refuse food, and look unfinished rather than dramatic.
- 2.Buying one or two as a curiosity. A solo glass cat fades to white and stops feeding inside a week.
- 3.Adding to a freshly cycled tank with any measurable ammonia. They react before any test strip turns colour.
- 4.Six or more, or do not buy. A solo glass cat goes pale and pins to a back corner within a week. Sensitive to ammonia spikes and sudden water changes.
About this species
Glass catfish are transparent Kryptopterus that you can see through to the spine. They shoal in midwater and pale to milky white when kept alone or stressed by ammonia.
- Adolfoi cory80L min · same group, comparable tank size
- Peppered Corydoras80L min · same group, comparable tank size
- Bronze corydoras100L min · same group, similar adult size
- Corydoras Catfish60L min · same group, similar adult size
- Julii Corydoras60L min · same group, similar adult size
- Panda Corydoras60L min · same group, similar adult size
- Salt and pepper cory / dwarf cory60L min · same fish family
- Sterba's Corydoras100L min · same group, similar adult size
- Adolfoi coryalso intermediate peaceful, similar tank size
- Bamboo Shrimpalso intermediate peaceful, similar tank size
- Black ruby barbalso intermediate peaceful, similar tank size
- Bolivian Ramalso intermediate peaceful, similar tank size
- Brown / hockey-stick pencilfishalso intermediate peaceful, similar tank size
- Cardinal Tetraalso intermediate peaceful, similar tank size
No reverse lookups listed yet.
Plan grid
Key limits are above. Here: pH band, swim level, bioload, and activity.
Swim zones
Care snapshot
Quick compare before you buy. Not a score of how “good” the fish is.
- Beginner ease32
- Peacefulness90
- Community fit79
- Small-tank fit100
- Hardiness44
- Energy24
Numbers are deterministic planning indices from Fishori fields — not a scientific score of your individual fish.
Example setups
Starting points only. Run the pair checker for every fish you add.
Rough 90L+ layout: one calm centrepiece, 8–12 small tetras/rasboras, 6–8 corydoras-type bottom fish — verify every name in the pair checker before buying.
Safer directions include: Dwarf Gourami, Harlequin Rasbora, Neon Tetra.
Prioritise 6+ of Glass Catfish in 80L+ with filtration sized for messy feeding — add only mates that already pass pair checks with this species.
Compatibility
Tank mates for Glass Catfish
Usually safer (engine GOOD): Dwarf Gourami, Harlequin Rasbora, Neon Tetra. Conditional (CAUTION — read the pair page before buying): Corydoras Catfish, Tiger Barb. Avoid (RISKY): Jack Dempsey, Oscar. Every name links to a live pair check — the lists are a shortlist, not a stocking plan.
Usually safer
Open a pair page with this fish as the starting point.
Needs planning
Read the blocking rule on each pair page before experimenting.
Usually avoid
Do-not-stock combinations on conservative hobby rules.
Compare with
Run a real pair check: Glass Catfish + Dwarf Gourami
Behaviour and temperament
Glass catfish are peaceful midwater schoolers that panic when kept in tiny groups. They ignore robust neighbours that leave them alone and disappear when the tank is loud, bright, or bare. Honest school size of six or more turns them from ghosts into a visible shoal.
What sets them off
- Sudden crowding
- Poor water quality
Fin nipping: Not a habitual fin-nipper; stressed or crowded individuals can still test fins.
Predation: Not a predator toward similarly sized community fish; fry and dwarf shrimp are still fair game for most species.
Territory: Not strongly territorial, but still needs room so its working space does not overlap the next fish.
Planted tanks: excellent — easy plant ideas
In the glass: typical and warning signs
- Six or more school in midwater as a moving transparent ribbon.
- They feed more confidently after lights soften than under bright noon glare.
- Constant hiding behind the filter in a group of three means under-stocking first.
- Hollow bellies after a week with only flake means food competition, not mystery illness.
- None toward tank mates; they lose contests rather than start them.
- In-school tight packing is security behaviour, not fighting.
- Add more glass catfish before you add another midwater species to “draw them out.”
- Move them out of any tank dominated by aggressive barbs or heavy current.
Fish behaviour can vary between individuals and tank setups. Always observe new fish closely after introduction.
Water, food, and grouping
Hardness
soft
Diet
carnivore
Glass catfish are shy midwater carnivores that take frozen foods and fine sinking pellets once settled. Flake alone often leaves the school underfed while bolder fish clear the surface. Feed after lights soften, and offer tiny portions the transparent bodies can finish without fouling the tank.
Shrimp & snails
Cherry shrimp and other dwarfs can coexist with peaceful small fish; baby shrimp are food for almost anything that finds them.
Schooling species — buy 6+ together. Smaller groups stress and lose colour.
- Hold 23 to 28 °C steadily on a real thermometer, not the dial on the heater.
- Aim for pH 6.5 to 7 and a hardness you can re-test in two weeks. A one-time strip in the shop car park is not a water test.
- Schooling species. Buy 6 or more from the same tank on the same day before adding any centrepiece fish.
- Tank volume meets or exceeds 80L published minimum for adults.
- You can stock at least 6 individuals (group welfare).
- Heater can hold 23–28°C without cooking cooler-water tank mates.
Explore and stocking hubs
Tank-mates hub, matching guides, category peers, and litre stocking lists around this species’ minimum tank.
Plan with tools
Check mates as pairs first, then add this fish in the tank builder for the full stocking.
Filtration & heating
A 80L minimum tank needs a filter rated for at least 320L/hr turnover and a heater to hold 23–28°C reliably.
Plant suggestions
Glass Catfish does well in planted tanks. Plants compatible with 23–28°C and pH 6.5–7:
Research: partially verified · Confidence: high · 3 linked source(s). We do not invent citations.
How Fishori evaluates compatibility (same logic as pair and tank tools).
- Seriously Fish. Kryptopterus vitreolus
Primary: aquarium size, water chemistry, behaviour, and compatibility (URL verified in upgrade script; recheck if site content changes).
- FishBase. Kryptopterus vitreolus
Secondary: taxonomy, distribution, and maximum length in nature; cross-check with aquarium import lines and measured tank parameters.
- Wikipedia. Kryptopterus vitreolus
Secondary: general species context; verify all husbandry numbers against a dedicated aquarium care sheet and your test kit, not a single table row.
Evidence notes
- The Seriously Fish profile for the binomial in this record was successfully reached as the primary aquarium reference.
- FishBase contributes natural-range size and habitat context. Translate those numbers through your heater, your water report, and your tank footprint before stocking.
- Wikipedia is only cited if the article URL returned OK. Use it for orientation, not as the only care sheet for an import.
- All compatibility text reflects typical hobby experience and the Fishori model. Individual fish, shop stress, and the order tank mates are added in can still defy a single-paragraph label.
Common questions about Glass Catfish
- How big do Glass Catfish get?
- Glass Catfish adults reach about 8 cm. Shop fish look smaller; stock for the adult length.
- What size tank does Glass Catfish need?
- 80L is the planning floor for adult swimming space and bioload. A 98L+ tank is the more comfortable long-term footprint. Length and depth matter as much as raw litres for active or territorial fish.
- Are Glass Catfish aggressive?
- Glass catfish are peaceful midwater schoolers that panic when kept in tiny groups. They ignore robust neighbours that leave them alone and disappear when the tank is loud, bright, or bare. Honest school size of six or more turns them from ghosts into a visible shoal.
- Do Glass Catfish need to be kept in a group?
- Schooling species — buy 6+ together. Smaller groups stress and lose colour.
- What is the most common mistake with Glass Catfish?
- Buying three glass catfish for a busy community is how keepers invent invisible, wasting fish. They need a school of six or more and calm company; under-stocked, they hide behind the filter and fade. Start with numbers and gentle neighbours, not with a novelty trio.
- What fish can live with Glass Catfish?
- The Glass Catfish profile lists Dwarf Gourami, Harlequin Rasbora, Neon Tetra among its safer pairings (engine-checked GOOD). Corydoras Catfish, Tiger Barb are conditional (CAUTION): workable only with the specific conditions on each pair page. Avoid Jack Dempsey, Oscar (RISKY). Run the pair checker for your exact water and tank size before stocking.