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 22 of 24
Not in the way the word 'peaceful' is usually meant: angelfish are cichlids — calm, slow swimmers that are nonetheless predators and territory holders. An adult angel will eat fish small enough to fit in its mouth, including the neon tetras it lived happily beside as a juvenile, and a bonded pair guarding eggs will…
Once they are settled, angelfish are reasonably hardy — but 'settled' is doing the work in that sentence, because young angels in a brand-new tank are exactly where they struggle. New aquariums swing in ammonia and temperature while they mature, and juveniles shipped, bagged and rehomed in quick succession arrive…
Angelfish can suit a beginner, but only one who starts with the tank the adult fish needs rather than the fish in the shop window: a tall aquarium of around 30 gallons or more, cycled and stable before the fish arrive. Juveniles look small and mild, yet they grow into tall, long-lived cichlids that claim space and may…
Buy tetras only into a fully cycled tank whose test results show no ammonia or nitrite, with the heater holding a steady tropical temperature day and night and the filter running quietly without battering small fish around. Test on separate days before buying, because one clear result cannot show whether warmth and…
Pick nerite snails for algae grazing without a growing population, because their eggs need brackish water to hatch and cannot hatch in a freshwater tank. Stock about one nerite for every 10 gallons so each snail finds enough algae to eat. Mystery snails are a controllable second option, since pairs lay visible egg…
That coin-sized baby becomes a fish around six inches long in body and eight or more inches tall once its long fins grow, and it can live for ten years or longer with good care. Plan on a tall tank of about 55 gallons for an adult pair, weekly water changes, and a fish that claims territory and may bully smaller…
Ask whether the site can hold a pond at least 3 feet deep and about 1,250 gallons for a final group of five adult koi, with level ground beside it for filtration and safe access to power and water. Check that the spot avoids heavy leaf fall, lawn runoff, and any slope that sends rain washing through the pond. Confirm…
Prepare in this order: set up a cycled quarantine tank with a mature filter, a heater if needed, and tested water showing no ammonia or nitrite; then question the closing-down keeper about species, adult sizes, recent deaths, any treatments used, feeding, and the tank's water readings. Take only the fish your water,…
Look at the pleco on the glass or in a viewing container, because a fish hiding in a corner cannot be judged. A healthy belly looks gently rounded: sunken and hollow suggests it has not been eating, while swollen is also a warning sign. Fins should be whole and spread, with no white spots, torn edges, clamped posture…
Know the adult before you buy the juvenile: a common pleco typically grows to between 12 and 24 inches (30 and 61 centimetres) and often lives for 10 to 15 years, so the juvenile becomes a large waste producer that needs a large tank. It will outgrow a standard community aquarium, uproot plants and rearrange decor as…
Check posture first: a sound betta holds itself upright and level and swims to different depths without sinking or struggling. Check the fins for tears, blackened edges, white spots, and fuzzy patches, and check that the body looks smooth and full rather than pinched or swollen. Check that both eyes are clear and…
Check general hardness (GH), carbonate hardness (KH), pH and total dissolved solids in your tap water before you fall for a shrimp species. GH tells you whether shrimp can build and moult their shells, KH shows how stable pH will stay, and a copper test matters because copper can harm shrimp even in tiny traces. Hardy…
Budget beyond the fish in two blocks. Building the pond costs $2,400 to $6,300, made up of excavation, liner, and edging at $900 to $2,400, filtration and pipework at $700 to $1,800, a pump and air pump at $400 to $1,100, and a quarantine setup at $400 to $1,000. Running it costs $600 to $1,500 a year, from…
Ask exactly what the fish eats now: the food type and form, the pellet or flake size, whether it floats or sinks, whether anything is offered frozen or live, how much is given, and how many times a day it is fed. Ask how eagerly this fish eats and whether it competes well. Then take home a supply of that same food and…
Ask what the line has been bred to show, how closely the parents are related, and how many generations the breeder has kept the line without adding new fish. Ask at what age males and females are separated, whether genuinely unmated females are available, what the fish eat and at what temperature they are raised, and…
Ask where the bettas are bred, how long they have been in the shop, and how long they rested after transport before going on sale. Ask how each fish is housed, how warm its water is kept, how often that water is changed, and what and how often it is fed. Ask whether any bettas nearby have shown illness, and listen for…
Buy and run everything before any fish arrive: the tank on a level stand built for its full weight, filter, heater checked against a separate thermometer, substrate, a lid and light, a water conditioner, and a liquid test kit. Then cycle the tank with no fish in it, feeding the filter an ammonia source and testing…
Prepare the tank before the fish exists in your life: choose at least 20 gallons (about 76 litres) for one fancy goldfish, fit a filter rated generously for a messy fish, add a secure lid, and complete a fishless cycle over four to six weeks until ammonia and nitrite test at zero. Buy the liquid test kit with the…
Judge a lid for jumping fish by fit and coverage: the best lid for your tank is a close-fitting one that covers the whole surface, leaves no gap around filter pipes, heater cables or feeding openings, and stays firmly in place when nudged. A solid cover slows evaporation and holds warm, humid air above the water,…
Build the plan around the adult who stays responsible, with the child as a trained helper: choose a modest filtered tank that is large enough to stay stable, cycle it fully without fish before any fish arrives, then stock one hardy species in the group size that species needs rather than a mixture of single fish. Give…
For a first fish or a common species, buy from a good local shop, where you can watch the individual fish swim, check the tank it lives in, and see it feed before you pay. Buy online when you want a species local shops rarely stock, using a specialist seller that ships overnight, and only when you can be home to…
Start with at least six corydoras, and make all six the same species. Corydoras are genuine group fish, and a group of six or more of one kind forages together, rests together, and behaves with the confidence that makes the species appealing. Mixed single fish of different corydoras species do not group together in…
Verify the claim under the fish's scientific name, not its shop label. Check that name in two independent sources and compare the adult sizes they give, because common names are shared by different species and that is how many stays-small claims survive. Look for photographs of mature fish in home tanks, and check…
Judge the tank you own by its footprint and the adult size of each cichlid, not by the juveniles in the shop tank. Choose species that use different zones, such as bottom dwellers alongside mid-water swimmers, match them for confidence so no timid fish is chased constantly, and keep only one male of each territorial…
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