Are you thinking about getting pets but don't have much time to care for them? Then I recommend getting a complete aquarium and some cold-water fish. These, unlike those that live in tropical climates, they do not need a thermostat; just make sure the water is clean and, of course, that they are fed several times a day. In addition, by tolerating temperate ambient temperatures, allow you to set up simple and stable aquariums with basic but well-sized equipment.
Although there are not many species available, the truth is that there are enough to set up a most interesting aquarium. Know the main characteristics of cold water fish and what care they require to live for several years. To enhance your well-being, it is advisable to add efficient filtration, good oxygenation and sufficient space, avoiding overcrowding and sudden changes in temperature.
What are cold water fish like?
Cold water fish are those that thrive without heating and can live with lower temperatures, around 10-24 ºC, provided the water quality is good and there is sufficient dissolved oxygen. In nature, they inhabit rivers, lakes, ponds, and temperate coastal areas with cool, well-oxygenated waters.
Their bodies can be rounded or stylized Depending on the species, they may have single or double fins, which are more or less long. In species such as fancy goldfish, the fins are strikingly developed; in others, such as barbs or orfes, the fins predominate. hydrodynamic forms that make active swimming easier for them.
If we talk about sight, it is not usually very good, but that is not a problem for them, since thanks to their nostrils and barbels that they have around their mouths can guide themselves and detect the presence of another animal that is approaching. Some varieties (telescope or bubble eyes) have very sensitive eyes, so they need decoration without edges.
In general, they are calm animals that swim slowly. For this reason, They can help you a lot to relax. However, there are differences: single-tailed goldfish (comet, shubunkin) are faster, while the fancy varieties (oranda, ranchu, ryukin, fantail) are more clumsy and it is advisable not to mix them with very fast swimmers who will take their food away.
What care do they require?
To keep healthy cold water fish, it is very important that we provide them with basic care, which are:
- Feeding: It's essential to feed them quality food, which can be found in pet stores. Feed should be based on their size, so small and medium-sized dogs should be given granulated food, while larger dogs should be given pellets. The frequency should be 2 to 3 times a day, and always the amount they can eat in seconds.
- Maintenance: It is highly advisable to keep them in glass ponds or aquariums, with a water whose pH is between 6,5 and 7,5. The place where they are located must be thoroughly cleaned between one and two times a week, putting the fish in a bowl or basin with water until their home has been left untouched.
- Powerful filtration: Even without heating, the aquarium needs a oversized filter capable of moving at least 5-7 times the tank volume per hour, with biological materials (tubes, matrix) to process ammonium and nitrites. In delicate varieties, a soft filtration at the outlet avoid excessive currents.
- Oxygenation and water movement: cold water fish consume lots of oxygen. Ensures good surface agitation (filter outlet facing the surface) and, if necessary, adds a aerator to improve gas exchange.
- Partial water changes: adopt a stable routine: renews 25-30% weekly with dechlorinated water at a similar temperature. This will keep nitrates low and prevent stress. It is preferable to bottom siphoning to total emptying or frequent transfer of fish.
- Parameters and temperature: pH between 6,5 and 7,5 and medium hardness are ideal. Controls ammonium and nitrites at 0 and keep nitrates below 40 mg/l. Avoid heat peaks and do not continuously exceed the 22-23 ºC indoors, as it speeds up your metabolism.
- Aquarium size: In small aquariums (<40 l) the options are limited. From 40 80-l Small species can be kept in groups (e.g., Chinese neon or medaka). For goldfish and carp, suitable are more than 100 l and free space for swimming.
- Safe decoration: Use plants and rocks without edges. Avoid sharp objects that can damage bulging eyes or long tails of fancy varieties. If you include plants, keep in mind that many species they peck at tender leaves.
- Compatibility: keep fish together similar size and speed. Don't mix slow-swimming varieties (bubble-eye, telescope) with very fast comets or shubunkin. Avoid opportunistic carnivorous species with fry.
- Outdoor ponds: provides shade in summer, good oxygenation, and sufficient depth for winter. In cold climates, ensure an ice-free zone remains for gas exchange.
PREMIUM QUALITY de peces of cold water
Now that you know what they are like and how they take care of themselves, it's time to find out what type de peces of cold water they are the most common in aquariums.
Pink beard
This is one of the fish that we most often find in pet stores. Its scientific name is puntius conchonius, and is native to Afghanistan, Pakistan, India, Nepal, Bangladesh, and Burma. It is very resistant, withstanding temperatures between 17 and 25 degrees Celsius. Once they reach adulthood, they measure 14 cm in length. In medium-sized aquariums, in groups and with good filtration, they show intense colours and active behavior.
Goldfish
The Goldfish, whose scientific name is Carassius auratusAlthough it is known more as carpÃn or red fish, it is by far one of the most popular. It is originally from China, and due to its size -about 15cm in adulthood- it is very suitable to have in aquariums of different sizes. There are many varieties, such as Bubble Eyes or Lion Head, but with any of them you can enjoy this hobby without having to worry.
To choose well it is important to distinguish between single tails (kite, shubunkin, sarasa), faster and more resistant, and fantasy varieties (Oranda, Ryukin, Ranchu, Fantail, Telescope, Pearl Scale, Skygazer) that require gentle current and calm companions. A good filter, weekly changes, and a varied diet (sinking pellets, blanched vegetables, and occasional protein) maintain their health and longevity.
Koi carp
Koi Carp, or Cyprinus carpio In scientific language, it is one of the most beloved fish. It is also native to China, although they inhabit all seas, except the cold ones at the poles. It is a relative of the common carp, and you should know that they can grow up to 70cm if the aquarium is large.
In practice, due to their size and bioload, they are recommended for spacious ponds and well oxygenated. In a pond, a specific diet for koi, Guidelines for raising koi fish and excess filtration are key to its coloration and growth.
Marble coridora
The coridora marble or coridora pepper, scientifically known by the name Corydoras paleatus, is one of the most recommended for beginners, since tolerates different qualities of water. It is native to the subtropical area of ​​South America, specifically inhabiting the rivers of Argentina, Bolivia, Brazil, Paraguay, and Uruguay. It grows up to 14 cm. In groups of at least 5-6 individuals, on fine substrates, they show social behaviors very entertaining.
gambusia
This fish, of the genus Gambusia, is very resistant, so much so that it can survive in both warm and cold waters. They are native to the rivers of most of the world, including Europe, Asia and Africa. They can be kept in small or medium aquariums, since they grow up to 14cm, but we need to know that this fish is carnivorous, and can eat the fry of other species de peces. By ello, Not recommended with species that breed in the aquarium if you want to keep the eggs.
Sun perch
This is one of the fish that stands out for its beautiful colors, but also for its adaptability, supporting from 4ºC to 22ºC. Its scientific name is Lepomis gibbosus, and it is originally from North America, although today, thanks mainly to the help of human beings, it is also found in Africa and Europe. It is a carnivorous animal, so It is not advisable to put it with other species de peces, nor should it be returned to its wild state. Adult males can grow up to a maximum of 20cm. It is preferable to keep it in single-species aquariums or controlled ponds.
Chinese neon (Tanichthys albonubes)
Small, peaceful and very showy, it tolerates fresh waters and is ideal for medium-sized aquariums in banks of 8 or moreIt gets along well with other calm species and appreciates vegetation and gentle currents.
Medaka or rice fish (Oryzias latipes)
Strong and adaptable, it supports wide temperature range. Perfect for simple aquariums or small ponds. In groups it displays interesting behaviors and relatively simple reproduction with plant shelters.
Blue and gold orfe (Leuciscus idus)
Fast and very active swimmers. Best in large ponds, with well-oxygenated water. In suitable spaces they coexist with koi and carp, providing dynamism to the whole.
Golden tench (Tinca tinca)
Golden variety of common tench. Slow-growing but of considerable final size; requires deep ponds and soft substrate. Not suitable for standard home aquariums.
Grass-eating grass carp (Ctenopharyngodon idella)
Voracious herbivore that helps control excess of plants in very large ponds. It needs a lot of space, highly oxygenated water and is not recommended for aquariums.
Baeri sturgeon (Acipenser baerii)
Kind of continuous swimming, requires cold, very clean, and well-oxygenated water. Exclusive for large ponds with high-performance filtration.
Chinese highfin shark (Myxociprinus asiaticus)
Spectacular for its juvenile dorsal fin and pattern. Although it tolerates fresh waters, reaches a large size and demands very large aquariums or ponds with current and high oxygenation. Not suitable for small aquariums.
To close the circle, remember that cold water fish combine beauty, variety and resistance as long as they have adequate filtration, oxygen and space. Choose compatible species, prioritize the Preventive Maintenance and planning the size of your aquarium will allow you to enjoy a stable and long-lasting setup without complications.
This concludes our special on coldwater fish. We hope it has helped you. choose your new tenantsDo you know more cold water fish and small size?
Which enjoy their company :).
