3,895 answers about fish & aquatics
A healthy aquarium is a balanced one — water chemistry, filtration, stocking and feeding all work together, and most fish problems start with the water. This page gathers the fish and aquatics library of KinsLe Answers in one place, organized by topic for freshwater and saltwater keepers alike. Every answer is original, written by KinsLe, and tied to a real KinsLe feature.
562 answers in Choosing & Adopting — page 12 of 24
A cardinal tetra grows to about an inch and a half as an adult, with an occasional well-grown female reaching a little beyond that. That is slightly larger than its famous relative the neon tetra, and the cardinal carries its signature colours further too — the red runs the full length of its lower body rather than…
An adult bronze corydoras grows to about two and a half to three inches, with females reaching the top of that range and growing noticeably plumper than the slimmer males. It is one of the larger and sturdier of the commonly kept corydoras, a thick-set bottom fish rather than a dainty one. That finished size is easy…
A Boeseman's rainbowfish grows to about four inches as an adult, with males reaching the top of that range — occasionally a little beyond in a large tank — and females finishing smaller and slimmer at around three to three and a half inches. The difference is visible in a mixed group, where the big, deep-bodied males…
A blue gourami typically grows to about five inches as an adult, with well-kept fish in spacious tanks occasionally reaching closer to six. Males and females finish at similar lengths, but a mature female looks deeper and rounder through the belly, while a male's dorsal fin comes to a point. That makes the blue…
An adult black skirt tetra reaches about two to two and a half inches long, with females growing a little larger and noticeably rounder than males. Length understates its presence, though: this is a deep-bodied, disc-shaped fish, and a full-grown female occupies far more visual and physical space than a slim tetra of…
Yes, white cloud mountain minnows are thoroughly peaceful community fish that nip nothing, chase nothing smaller into corners, and busy themselves with their own shoal. The condition is temperature, not temperament: they are cool-water fish that fade in a warm tropical setup, so their community must be built from…
Yes — threadfin rainbowfish are among the most peaceful community fish available, so gentle that the bigger risk is other fish harming them. Males court females with long, delicate fin extensions and never trouble tankmates, but those trailing fins invite nipping, and their tiny mouths and shy feeding lose out beside…
Yes, dwarf rainbowfish are peaceful community fish and one of the easier rainbows to fit into a shared tank. They are active midwater swimmers that display and spar briefly among themselves but do not hunt, nip, or bully other species. Their real requirements are companions of comparable size, food small enough for…
Yes — Boeseman's rainbowfish are genuinely peaceful community fish, with no interest in fighting, fin-nipping, or bullying tankmates. Their limits are size and energy rather than temper: adults reach around four inches, swim fast and constantly, and crowd eagerly at food, so tiny, shy, or very slow tankmates can be…
Cycling grows the colonies of bacteria that make a tank survivable: fish waste releases ammonia, which burns gills and poisons fish, and only an established colony converts it first to nitrite — also toxic — and then on to the less harmful nitrate you remove with water changes. Those bacteria grow on filter media and…
A tropical aquarium's running costs arrive as a steady drip rather than bills: staple and frozen foods, water conditioner used at every change, filter media, test kit refills, and the electricity drawn around the clock by the heater, light and filter. Layered on top are the irregular costs — a heater or pump that…
The inch-of-fish rule says you may keep one inch of fish per gallon of water, and it misleads because length is nearly the least important thing about a fish's impact on a tank. A slim neon tetra and a deep-bodied goldfish of the same length produce very different amounts of waste, the ruler says nothing about the…
The zebra danio is the classic answer: it tolerates a wide temperature range, stays active and visible, eats almost anything offered, and shrugs off the small water-quality wobbles that defeat more delicate fish while a beginner finds their feet. White cloud mountain minnows run it close, and hardy corydoras and…
A fifty-five gallon community rewards bigger schools rather than a longer species list: fifteen to twenty congo tetras or a group of boesemani rainbowfish for the middle, a pair of pearl gouramis or a small group of angelfish as the centrepiece, a school of corydoras or yoyo loaches along the bottom, and a bristlenose…
A twenty-gallon works best stocked in layers: a school of twelve to fifteen small tetras or rasboras for the middle, a calm centrepiece such as a honey gourami, a group of six or more corydoras working the bottom, and shrimp or snails as the cleaning crew. The twenty-gallon long suits this better than the tall…
Stock a ten-gallon around one plan rather than a little of everything: a betta with a couple of snails, a school of eight to ten ember tetras or chili rasboras with cherry shrimp, or a group of male Endler's livebearers with pygmy corydoras below. Each plan keeps every fish small as an adult, fills one or two levels…
Plenty of aquarium favourites are genuinely happy at warm room temperature: white cloud mountain minnows, zebra danios, guppies, platies, medaka ricefish, paradise fish and cherry barbs all thrive in the low-to-mid seventies that a warm house holds. The condition is stability rather than a number — the tank should sit…
The best fish for a child's first aquarium are hardy, active species that forgive beginner mistakes: white cloud mountain minnows, zebra danios, platies and guppies all fit, in a ten to twenty gallon tank that holds conditions steadier than a bowl. Goldfish are the classic trap — they grow large, produce waste and…
The first year of owning guppies is a year of multiplication: a starting group settles in, the females begin producing fry every month, and a tank that looked spacious in spring can be crowded by autumn. Between the babies, the year involves feeding a community several meals, keeping plants trimmed as they fill in,…
The first year with goldfish is mostly a year of growth and routine: a fish bought at a couple of inches can put on several inches in twelve months, and fancy types fill out into round, heavy-bodied adults. The early months are about the tank settling in, with filter bacteria establishing and water testing becoming a…
The first year with a betta is a front-row seat to a personality: within weeks he learns the feeding routine and greets you at the glass, his fins and color finish developing over the first months, and bubble nests, resting habits, and favorite spots become familiar landmarks. The year's real work is consistency —…
The first year of angelfish keeping is a story of fast growth and emerging personalities: juveniles the size of a coin eat several small meals a day and double in size within months, hierarchies form as they mature, and by the end of the year a bonded pair may be cleaning a leaf and claiming a corner of the tank.…
A day with zebra danios is the liveliest in the hobby: the school is racing the top of the tank from lights-on, takes two quick feeds of small food at the surface, and spends every hour chasing, displaying, and weaving through the current. Daily care is genuinely five minutes — feed, glance at the flow and…
A siamese algae eater spends the day working: grazing algae off leaves and glass, resting draped on a broad leaf, and patrolling the tank in short bursts, so your daily care is a small supplementary feed in the evening and a check that he is eating algae rather than only stealing the other fishes' food. Older algae…
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