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.
649 answers in Home & Lifestyle — page 17 of 28
A white cloud mountain minnow needs a 10-gallon tank at minimum, with a 20-gallon long better for a full school - and no heater. These are cool-water fish from mountain streams, happiest in the 60s and low 70s Fahrenheit, and a standard heated tropical setup quietly shortens their lives. A school of six to eight in an…
A tiger barb needs a 30-gallon tank, because the school that keeps tiger barbs peaceful is bigger than most people expect. Eight to ten fish is the working minimum - in small groups the school's hierarchy collapses onto the weakest fish and onto any slow, long-finned tank mate in reach. In a long 30-gallon, a full…
A serpae tetra needs a 20-gallon tank, sized for the school that keeps this fish honest. Serpaes have a fin-nipping reputation, but it is mostly a group-size problem: kept in threes and fours they pick on tank mates, while a school of eight to twelve turns that energy inward and behaves. Give them planting to break up…
A rummy nose tetra needs a 20-gallon tank at minimum, and a longer tank is worth more than a taller one. Rummies are the tightest schoolers in the tetra family, moving as a single unit, and a school of eight to ten needs the swimming length to do it. They are also genuinely sensitive fish that belong only in a mature,…
A rosy barb needs a 30-gallon tank for a school, because this is a bigger, busier barb than its price tag suggests. Males grow to three inches or more and flush deep rose-red, and in pairs or trios they spend their energy pestering tank mates instead of each other. A school of six or more in a 30-gallon keeps the…
A leopard danio needs a 20-gallon long tank - the length is the requirement, not just the gallon count. These spotted danios swim fast, high, and almost nonstop, and a tall 20-gallon gives them far less usable room than a long one with the same volume. Fit a tight lid, since startled danios jump. For cool-water tank…
A lemon tetra needs a 20-gallon tank for the size of school this species actually thrives in. Lemon tetras reach about two inches and are noticeably deep-bodied, and in groups smaller than eight they turn skittish and lose the soft yellow color and red eye that make them worth keeping. In a planted 20-gallon, a school…
A gold barb needs a 20-gallon tank at minimum, and a 30-gallon is the comfortable choice for a school. Gold barbs grow to about three inches and swim almost constantly, so a group of six or more kept in a small tank ends up cramped, pale, and restless within months. They are hardy fish, but hardy is not the same as…
A glowlight tetra needs a 10-gallon tank at minimum, and 20 gallons gives a full school of eight to ten the room to spread out. The fish itself is only about an inch and a half long, but it is a true schooling species that washes out and hides when kept in twos and threes. Their orange stripe shows best in glowlights…
A Congo tetra needs a 30-gallon tank at minimum, and a 40-gallon with a four-foot footprint suits a school far better. Males grow past three inches, carry long flowing fins, and spend the day cruising and displaying in open water, so a school of six or more runs out of room quickly in anything shorter. Before you buy,…
A chili rasbora can be kept in a 5-gallon nano tank, but a 10-gallon is the safer and kinder minimum for most homes. Adults stay under an inch long, yet they are shy fish that only relax and color up in schools of ten or more, and the extra water volume forgives the small mistakes that swing conditions fast in tiny…
A celestial pearl danio needs a minimum of 10 gallons, and a 20-gallon long is the better buy for a proper group. The fish itself barely reaches an inch, but males spar and display constantly, and a longer, densely planted tank lets the losers of those contests slip out of sight instead of living stressed. Whatever…
A cardinal tetra needs a tank of at least twenty gallons, long rather than tall, because cardinals are schooling fish at their best in groups of eight to ten or more and need a horizontal run to school along. A practical note: put the school into a mature, stable tank rather than a brand-new setup, since cardinals are…
A black skirt tetra needs a tank of at least twenty gallons, because it is a schooling fish that should live in a group of six or more and each deep-bodied adult needs room to hold its place in the school. A practical note: choose a longer twenty-gallon over a tall one, since black skirts swim in the middle level and…
White cloud mountain minnows should be kept in a group of six or more, and eight to ten shows their schooling and fin displays at their best. A practical note: white clouds are cool-water fish that thrive without a heater in a normal room, so group them with other temperate species rather than tropical fish that need…
Tiger barbs should be kept in a group of at least seven, and ten or more is better, because their nipping and chasing are spread across a big group instead of landing on tank mates. A practical note: plan the tank around the school — a twenty-nine-gallon setup with room to run, and companions that are fast and…
Serpae tetras should be kept in a group of six at minimum, and eight to ten is the wiser number because under-grouped serpaes are famous for nipping the fins of their tank mates. A practical note: the bigger the serpae school, the more their chasing stays inside it, so spend on more serpaes before adding any…
Rosy barbs should be kept in a group of six or more, planned around their adult size of around four inches, so a school really needs a thirty-gallon tank or larger with swimming length. A practical note: keep at least two females for every male, because rosy males in breeding colour court persistently and a lone…
Odessa barbs should be kept in a group of six to eight or more, with a mix of males and females, because the males' famous red colour only develops when they have rivals to display to and females to impress. A practical note: buy the group from one tank at the shop so sizes match, since a small latecomer can be…
Leopard danios should be kept in a group of six or more, and their spotted pattern and constant motion only settle into healthy schooling at that size. A practical note: danios are powerful jumpers and relentless swimmers, so pair the group with a tight lid and the longest tank you can offer rather than a tall one.…
Lemon tetras look and behave their best in a group of at least six, and eight to ten in a twenty-gallon tank turns their soft yellow into a real display. A practical note: colour is the tell — a washed-out lemon tetra is usually a lonely or unsettled one, so count the school before blaming food or lighting. Sharing…
Keep gold barbs in a group of six or more, because a lone barb or a pair turns shy or pushy, while a proper group keeps their energy focused on each other. A practical note for community tanks: gold barbs grow to about three inches and swim hard, so give the group a tank with real length rather than tall, narrow…
Glowlight tetras should live in a group of six at the very least, with eight to ten giving the relaxed schooling and bright neon stripe this species is kept for. One practical note: their glow shows best under slightly dimmed light with a dark background, so judge the group after the tank lights settle rather than…
Keep ember tetras in a group of at least eight, and ten or more is better, because these tiny schooling fish feel exposed and hide when their numbers drop. A practical note for a nano setup: add the whole group at once to a cycled, planted tank so no latecomer is singled out and the biofilter adjusts in one step.…
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.