Chezur
Responsible fishkeeping decisions
Profiles built around adult size, behaviour, social needs and usable space.
What you will find
- Temperate and tropical fish
- Compatibility beyond water values
- Welfare before stocking density
Freshwater fish
Choosing freshwater aquarium fish by conditions
How to assess adult size, social behaviour and swimming zone, cross-check water parameters that can remain stable and make a decision from compatibility of diet, territory and waste load.
Tropical fish versus coldwater fish
How to assess the actual thermal range of each species, cross-check seasonal heating or cooling requirements and make a decision from a community compatible throughout the year.
Planning a community aquarium
How to assess adult size, social number and swimming levels, cross-check overlap in temperature, hardness and current and make a decision from introduction order and available territories.
Freshwater predatory fish in aquariums
How to assess mouth size, potential prey and adult size, cross-check a complete diet without routine live feeder fish and make a decision from space, waste load and tankmate safety.
How many fish fit? Why centimetres per litre fails
How to assess volume, surface area and tank footprint, cross-check adult mass, activity, territory and group needs and make a decision from maintenance capacity and parameter trends.
Coldwater aquariums
Coldwater fish suitable for aquariums
How to assess year-round temperature and oxygen availability, cross-check adult size, activity and social requirements and make a decision from legally sourced species that do not require a pond.
Temperature planning for coldwater fish
How to assess species-specific range and tolerated seasonal change, cross-check lower oxygen availability as water warms and make a decision from a heatwave response rather than winter planning alone.
Goldfish: adult size, waste load and real needs
How to assess variety, adult size and horizontal space, cross-check heavy waste production and oxygen demand and make a decision from social needs, substrate and maintainable filtration.
Goldfish alternatives for different setups
How to assess stable temperature and available volume, cross-check activity, social number and swimming length and make a decision from a species whose adult size genuinely fits.
Compatibility in a coldwater aquarium
How to assess overlap in temperature and current, cross-check size difference, diet and feeding speed and make a decision from space for groups and refuges without crowding.
Marine and brackish
Choosing saltwater aquarium fish
How to assess volume, maturity and salinity stability, cross-check adult size, territory and specialised diet and make a decision from compatibility with corals, invertebrates and fish.
Is there a freshwater clownfish?
How to assess true clownfish as marine Amphiprion species, cross-check trade names that confuse unrelated fish and make a decision from a stable marine system for real clownfish.
Beginner marine fish: what hardy should mean
How to assess accepted food and responsible origin, cross-check adult size, aggression and territory and make a decision from a mature system with quarantine and maintenance capacity.
Fish for a brackish aquarium
How to assess a measured salinity target rather than spoonfuls, cross-check species origin and life stage and make a decision from gradual acclimation and freshwater evaporation top-off.
Freshwater versus marine aquarium operation
How to assess salinity, water preparation and maturation, cross-check equipment, circulation and nutrient export and make a decision from cost, livestock availability and error margin.
Compatibility
Compatible tropical fish: a verification matrix
How to assess overlap in temperature, pH and hardness, cross-check adult size, mouth, territory and swimming speed and make a decision from social number and space in every tank level.
What makes two fish species incompatible
How to assess predation, aggression and resource competition, cross-check water or current requirements without overlap and make a decision from early exclusion and chronic stress signs.
Shoal, group, pair or solitary life
How to assess the species’ natural social structure, cross-check minimum number and sex ratio where relevant and make a decision from space to gather, withdraw and hold territory.
Predation, mouth size and size differences
How to assess adult size and ability to swallow tankmates, cross-check uneven growth and nocturnal activity and make a decision from refuges that reduce encounters without excusing unsafe mixing.
Adding livestock to an established community
How to assess quarantine and prior observation, cross-check biofilter capacity and occupied territories and make a decision from staged introduction with a removal plan.
Popular and beginner fish
Aquarium temperature for guppies
How to assess a stable range suited to the stock’s origin, cross-check oxygen, metabolism and reproduction as temperature rises and make a decision from thermal compatibility with every tankmate.
Keeping a betta in a community aquarium
How to assess individual temperament, fins and current, cross-check tankmates without fin-nipping or surface competition and make a decision from a separation plan and surface-air access.
Neon tetras: group, water and tankmates
How to assess a sufficient group that limits insecurity, cross-check stable water, horizontal space and subdued areas and make a decision from small tankmates without predation or relentless activity.
Platies and mollies: important differences
How to assess larger adult size and space needs of many mollies, cross-check hardness preferences and salinity tolerance and make a decision from reproduction, sex ratio and future load.
What should “beginner fish” actually mean?
How to assess reasonable tolerance without accepting poor conditions, cross-check accessible diet, social number and correct volume and make a decision from the keeper’s ability to maintain stability.
Livebearers
Guppies: group, sex ratio and bioload
How to assess persistent reproductive pursuit and sex ratio, cross-check juvenile growth and future population and make a decision from filtration and a responsible plan for surplus fish.
Mollies: water, adult size and social needs
How to assess variety and actual adult size, cross-check stable mineral-rich water and source acclimation and make a decision from group, plant-rich diet and swimming space.
Platies: care and compatibility
How to assess social group and pressure on females, cross-check stable water with suitable hardness and make a decision from continuous reproduction and aquarium capacity.
Swordtails: space and tankmates
How to assess swimming length and adult size including the sword, cross-check territorial males and sex ratio and make a decision from a secure lid, planting and compatible active fish.
Responsible livebearer population control
How to assess sex separation before overcrowding, cross-check stored sperm and repeated broods and make a decision from responsible rehoming without release.
Cichlids
Freshwater cichlids: diversity before stocking
How to assess geographic origin and water chemistry, cross-check adult size and pair, colony or group structure and make a decision from territory, digging and filtration capacity.
African versus American cichlids
How to assess lake or drainage origin, hardness and pH, cross-check breeding behaviour and territorial structure and make a decision from adult size, diet and functional hardscape.
Lake Malawi cichlid compatibility
How to assess mbuna, haplochromines and diet, cross-check sex ratio, colour and intraspecific aggression and make a decision from rockwork, footprint and filtration for high load.
Dwarf cichlids: substantial territory in a small body
How to assess pair or harem structure by species, cross-check caves, sight breaks and bottom territory and make a decision from tankmates that avoid breeding sites and shelters.
Territory, waste and filtration for cichlids
How to assess visual boundaries and refuge count, cross-check waste, digging and an accessible prefilter and make a decision from circulation that retains calmer territorial areas.
Bottom-dwelling fish
Choosing freshwater bottom-dwelling fish without myths
How to assess species, adult size and social structure, cross-check substrate, oxygen and usable bottom area and make a decision from a complete diet that reaches the animal.
Corydoras: group, substrate and feeding
How to assess correct species and a sufficient social group, cross-check clean sand or smooth fine gravel and make a decision from targeted food delivered when they can access it.
Plecos: adult size and the cleaner myth
How to assess accurate identification among very different species, cross-check adult size, wood, diet and waste production and make a decision from bottom footprint and nocturnal shelter.
Loaches: social needs, activity and space
How to assess species, group size and adult size, cross-check safe substrate, shelter and oxygenated current and make a decision from nocturnal activity and compatibility with snails or slow fish.
Why no fish replaces aquarium cleaning
How to assess waste transformed rather than removed when eaten, cross-check the cleaner animal’s own welfare needs and make a decision from siphoning, food control and filter maintenance.
Welfare and behaviour
How to feed aquarium fish correctly
How to assess species diet and appropriate particle size, cross-check observed consumption rather than a universal number of minutes and make a decision from body condition, growth and waste as feedback.
Fish sleep, rest and normal behaviour
How to assess the species’ day or night rhythm, cross-check usual posture, colour and resting location and make a decision from rest versus abnormal breathing or balance.
Fish acclimation and quarantine
How to assess temperature and chemistry differences between waters, cross-check a cycled quarantine container with separate equipment and make a decision from enough observation before populations meet.
General fish stress signs and when to seek help
How to assess breathing, balance, appetite, skin and behaviour, cross-check ammonia, nitrite, temperature and recent changes and make a decision from risk isolation and an aquatic professional when decline continues.
Responsible rehoming and invasive-species prevention
How to assess adult size and future capacity before purchase, cross-check adoption, responsible trade or local authority options and make a decision from safe transport without releasing fish, plants or water.