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.
297 answers in Young Pets — page 1 of 13
A healthy newborn rummy-nose tetra is tiny, mostly translucent, and dominated by large dark eyes, with a small yolk sac under the belly that shrinks steadily over the first days. At first the fry rest and wiggle near where they hatched, then become free-swimming, holding themselves level in the water rather than…
A rummy-nose tetra grows fastest in its first months, slows as its red nose and banded tail reach full colour, and is close to its full adult size of roughly two inches once fully mature, with smaller gains in depth and condition after that. Growth is not a switch: a well-fed youngster in clean, warm water reaches…
Baby rummy-nose tetras eat microscopic foods at first: in their earliest free-swimming days they need infusoria or a prepared liquid fry food, then graduate to microworms and freshly hatched baby brine shrimp as their mouths grow, with finely powdered fry food filling gaps between live feeds. Offer tiny amounts…
Young rummy-nose tetras can move into the main tank when they are too large to fit in an adult's mouth, eating the same foods as the adults, swimming strongly in a current, and showing the red nose and striped tail pattern developing. For most youngsters that point comes after several weeks of growth in a separate…
You can usually tell a young celestial pearl danio's sex once its adult colours develop: males become vivid, with deeper body colour, bright orange-red fins edged in black, and bold spotting, while females stay paler with clearer fins and a rounder belly. Young fish all look female at first, so wait until the group is…
A healthy newborn celestial pearl danio is tiny and mostly translucent, with a visible yolk sac at first, dark eyes that look large for its body, and a slender, almost glassy outline. In the first days it rests on plants or the tank floor more than it swims, then begins short, darting movements as the yolk is…
A celestial pearl danio grows fastest in its first few months and reaches close to its full adult size — only about an inch long — within roughly the first half year of life, with slower filling-out afterwards. Growth is quickest when the young fish gets frequent small meals, warm stable water, and room away from…
Baby celestial pearl danios start on foods almost too small to see, such as infusoria and other microscopic life living in moss and plant matter from a mature tank. As they grow over the first weeks they graduate to tiny live foods like vinegar eels and microworms, then newly hatched baby brine shrimp and finely…
Young celestial pearl danios can move into the main tank once they are clearly too big to fit in an adult's mouth, swimming strongly in open water, and competing confidently at feeding time. Size matters more than age, because adults may chase or eat much smaller juveniles that still look like live food. Introduce…
A zebra danio grows quickly and reaches its full adult size of about two to two and a half inches within four to six months. Females finish rounder and slightly larger than the slimmer males, and both sexes show their bold horizontal stripes clearly long before growth fully plateaus. Because zebra danios are…
A pearl gourami reaches its full adult size of about four to five inches at roughly twelve to eighteen months, growing steadily rather than in spurts. Males develop their orange-red throat and longer, flowing fins as they mature, while females stay a little smaller and rounder with shorter fins. Calm tank mates,…
A kuhli loach grows slowly and reaches its full adult length of about four to five inches at roughly twelve to eighteen months, then mainly thickens rather than lengthens. Because kuhli loaches hide by day and forage at night, owners often miss the gradual change and are surprised by a suddenly long loach under the…
A harlequin rasbora reaches its full adult size of just under two inches at roughly nine to twelve months, with the fastest growth in its first few months. Its deep body and copper colour fill out as it matures, and males usually look slightly slimmer and brighter than females at the same length. Because harlequin…
A guppy reaches close to its full adult size by about four to six months, growing fastest in its first weeks of life. Adult males usually finish around an inch and a half long with their colour and tail shape fully developed, while females grow larger, often past two inches, and keep filling out in the body a little…
A goldfish does most of its growing during its first eighteen to twenty-four months, then slows to a near stop, although tiny gains can continue for much of its life. A streamlined common goldfish kept with generous space can pass ten inches, while a round-bodied fancy goldfish usually settles nearer six to eight…
A corydoras catfish grows quickly through its first months, then slows and typically reaches its full adult size within roughly its first year, though the final size depends heavily on the species — from tiny pygmy types to stout bronze corydoras several times larger. Females usually finish bigger and deeper-bodied…
A bristlenose pleco does most of its growing in its first year or so, then slows markedly and typically reaches its full adult size — around four to five inches including the tail — during its second year. Males develop their namesake snout bristles well before growth fully stops, so bristles alone do not mean a fish…
Young zebra danios can move into the main tank when they are strong, horizontal swimmers that school in open water and are too large for an adult danio or similar tankmate to swallow. That usually means well-grown youngsters with stripes clearly showing, not wispy fry fresh off the spawning mop. Zebra danios are fast…
Young pearl gouramis can move into the main tank when they are breathing comfortably at the surface with a fully working labyrinth organ, feeding boldly at the top, and large enough that adult tankmates ignore them. Pearl gouramis are gentle, but an adult male can be possessive of surface territory, so move youngsters…
Young kuhli loaches can move into the main tank when they are burrowing and foraging confidently at night, holding their banded pattern and body condition, and are long and thick enough that the main tank's larger fish will not treat them as worms. Adult kuhli loaches are peaceful and social, so other tankmates set…
Young harlequin rasboras can move into the main tank when they are schooling confidently, feeding in open water, and large enough that the main tank's biggest fish cannot eat them — adult harlequin rasboras themselves are peaceful schoolmates. The copper colour and dark wedge marking should be clearly developing, a…
Young guppies can move into the main tank when they are too large for an adult guppy's mouth — usually once they are stout, free-swimming, and well past the slender newborn stage — and when they hold their own at feeding. Adult guppies will eat fry that still fit in a mouth, so early cover matters even after the move.…
Young goldfish can move in with adults when they swim strongly against the filter flow, compete confidently at the surface or mid-water for food, and are too large for an adult goldfish to fit in its mouth. That point depends on growth, not a calendar date, and slower fancy youngsters need longer than streamlined…
Young corydoras catfish can move into the main tank when they are actively foraging on their own, their barbels are full-length and undamaged, and they are too big for the largest tankmate's mouth — commonly once they reach roughly two-thirds of adult length. Adult corydoras are gentle and will not threaten them, so…
Can't find your question? Ask it here. We answer reader questions in KinsLe Answers — and we'll email you when yours is published.
KinsLe is launching soon — and the waitlist hears the date first. Join for launch updates and first access when the app opens.
We email you about the launch. Unsubscribe anytime.