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 17 of 24
Yes — this is one of the friendliest bottom-dweller pairings in the hobby. Both species are peaceful, social and completely unarmed, and they share the same soft sand and shadowy corners without competing for them or for each other's company. Keep each species in its own proper group, since both are schooling fish in…
Yes — these two generally live together peacefully because they barely share the same tank. The bristlenose works the bottom and the night shift, grazing algae, rasping driftwood and hiding away by day, while the angelfish hold the middle and upper water in full view. Provide a cave the pleco can claim as its own,…
Possible, but this pairing asks more of the setup than most betta tanks offer. Neon tetras kept in a small group may nip at a betta's flowing fins, while a betta with a hunting streak may chase and pick at the school. It works best in a longer tank with a genuinely large school — ten or more — so the tetras stay…
Yes — mystery snails are among the safest companions a betta can have. A snail is slow, keeps entirely to itself, and can pull shut into its shell whenever a curious betta investigates, so there is almost nothing for the betta to fight with. A few bettas do nip at a snail's long feelers, mistaking them for worms, so…
Usually this is a poor match, and the reason is mistaken identity: a male guppy's bright colours and long flowing tail read to a betta as another male betta — a rival — and bettas have been known to chase and tear at them. The traffic runs both ways, too, since guppies sometimes nip at a betta's own long fins. A few…
Yes — this is one of the most reliable betta combinations you can choose. Corydoras live on the bottom, keep entirely to themselves, and wear tough overlapping armour plates, while the betta rules the surface layers, so the two rarely even cross paths. Keep the corydoras in a group of six or more over soft sand, give…
Sometimes — and it depends entirely on the individual betta. Many bettas ignore adult cherry shrimp completely; others hunt them methodically from the first hour, and baby shrimp are eaten by almost every betta that notices them. Success comes from cover and order: dense moss and planting, the shrimp established in…
This pairing is riskier than it looks in shop tanks, where the angelfish are always juveniles. In the wild, angelfish hunt small tetras, and once an angel is full-grown a neon tetra is exactly bite-sized; many keepers watch a thriving school quietly shrink over a few months. Angels raised from small alongside neons…
It can work in a large, heavily planted tank, but this is one of the classic combinations that turns entirely on size: a full-grown angelfish sees a small guppy — and above all guppy fry — as food, and an angelfish's mouth is bigger than it looks. Adult guppies often live alongside angels unmolested while every fry…
Yes — clown plecos are peaceful community fish, with two catches: they are shy, and they need wood. A clown pleco spends the day hidden and comes out at night to graze, rasping on driftwood, which forms part of its diet rather than just décor. It will not bother other fish, though two plecos in a small tank can…
If you want the colony to stay one colour, keep one colour: the red, yellow, blue and orange cherry shrimp in the shops are selectively bred lines of the same species, and mixed lines interbreed freely. Their offspring blend the parents' genetics and, generation by generation, drift back toward the plain wild-type…
Consider what a pair actually means before you buy one: two angelfish are not automatically a pair, and two males or an unmatched duo can turn a calm tank into a slow war of chasing and torn fins. A proven, bonded pair is the safer purchase, but it claims territory, may spawn repeatedly and will defend its eggs…
Buy with your eyes on the failure points: run a fingertip along every silicone seam feeling for lifting, bubbles or gaps, inspect each corner for chips in the glass edges, and check any centre brace for cracks or tired plastic. Then insist on a fill test — the tank filled completely, on a level surface somewhere a…
Ask four questions first: how big a tank can you honestly house, do you want heated water or room-temperature water, how long a commitment can you take on, and do you want one or two statement fish or a busy mixed community? Fancy goldfish need far more water per fish than their size suggests and can live well over a…
Ten gallons is the bare minimum for zebra danios and a twenty-gallon long is what actually suits them, because these two-inch fish spend the day racing the length of the tank in a school. Keep at least six, and choose floor length over height — they live in the top layer and barely use deep water. A tight lid is part…
Allow thirty gallons for a single siamese algae eater, and think in length rather than volume: the small striped juvenile in the shop becomes a six-inch adult that swims the tank end to end all day. A group of five or more — the better way to keep them — needs fifty-five gallons, so their chasing has room to dissolve.…
Thirty gallons is the minimum for pearl gouramis, and it should be a long, calm tank rather than a tall one. An adult pearl reaches four to five inches, moves slowly and deliberately, and needs open surface water it can rise to for air, plus planted retreats for when a male turns territorial. One male with one or two…
A twenty-gallon long is the sensible minimum for kuhli loaches, because what they use is floor, not height: a group of six or more needs a long footprint of sand to sift, burrow in and drape across. A taller tank with the same gallons but half the floor serves them worse. Fewer than six is false economy — a lone kuhli…
Plan on ten gallons as the minimum, and only for the school itself: harlequins belong in groups of at least eight to ten, and the tank is sized for that school, not for one two-inch fish. A twenty-gallon long is the kinder home, giving the school open mid-water to hold together over a longer swimming run. In the…
A 10-gallon tank is the practical minimum for a small group of guppies, and a 20-gallon gives you far more breathing room once babies arrive. Guppies are livebearers, so a single pregnant female can turn a comfortable stocking level into overcrowding within weeks; plan the tank around the colony you will have, not the…
Forget the bowl: a single fancy goldfish needs a minimum of about thirty gallons, with roughly ten more gallons for each additional fish, because goldfish grow large, live for decades and produce heavy waste. Sleek single-tailed goldfish — commons and comets — outgrow indoor tanks honestly and belong in fifty-five to…
The minimum for corydoras is a twenty-gallon tank with a decent footprint, sized for the school rather than the individual fish: corydoras are shoaling catfish that should live in groups of six or more, and the group needs floor to forage. A long twenty-gallon suits the common bronze and peppered corys; the larger…
Cherry shrimp can live in as little as five gallons, but ten gallons is the wiser minimum for a first colony: shrimp are far more sensitive to water swings than to space, and a bigger volume holds temperature and chemistry steadier while the colony grows into it. Start with ten or so shrimp and they will breed to fill…
A single bristlenose pleco needs a minimum of about thirty gallons to be safe — twenty is quoted for a juvenile, but the adult is a five-inch fish that produces waste out of all proportion to its size, and the tank must dilute it. Floor space matters more than depth, and a piece of driftwood is not decoration for this…
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