Killifish Species Facts | Aquarium Guide, Care, Insertion & Feed

Last updated on December 24th, 2022 at 11:06 am

Killifish species have their character – while some are loners and need their territory, many killifish can be kept in pairs or whole schools. In any case, get advice from a specialist before buying which killifish species are suitable for your planned aquarium. In general, killifish that are kept in a community aquarium must have the same demands for light, water temperature, and quality.

Killifish Care Facts

If you want to take good care of your killifish, then ensure optimal and species-appropriate water conditions in the aquarium. Of course, you should feed your killifish healthy and make sure that the aquarium technology always works.

Killifish diseases are often due to poor husbandry conditions. If you regularly pay attention to your aquarium’s cleanliness and ecological balance, there should be hardly any killifish diseases. If the killifish get sick, there are effective medicines.

Typical signs of killifish diseases are, e.g., B. “chafing,” breathing problems, injuries, and/or frayed fins. Delimitation and lethargy in sociable killifish can also be an indication of a disease.

You Should Pay Attention to This:

Symptoms Possible Cause
Small white spots on the scales and fins Ichthyol (spot disease)
Yellow spots (gold dust) Velvet disease
Killifish gasp for air on the water surface Water quality, an infestation of the gills
Excessive mucus formation, milky or slightly gray skin tint Water quality, Costia disease
Mucous membrane drips from the gills Water quality, an infestation of the gills
Killifish scour objects Water quality, skin infestation with parasites
Dull eyes Water quality, injuries, bacterial infection
Inflammation on fins and the body Water quality, bacterial infestation
Ulcers Bacteria
The cotton-like covering on the body Mold
Dark coloring / mattness Water quality, possible parasite infestation
Rapid or irregular breathing Water quality, an infestation of the gills
Attacked mouth and fluffy fluff on the head Muzzle

Aquarium for Killifish Species

There are two ways to choose your aquarium: determine the size of the aquarium according to the number of fish desired, or determine the number of fish according to the size of the aquarium that you can install.

Having a filter is mandatory, and just as important as the liter in your aquarium. You also need to adapt the size of the aquarium to the size of your fish, growing the fish will need more space. If possible, choose an aquarium that is slightly larger in capacity, compared to your needs. This will allow the fish to develop better and faster.

When you have decided on the size of your aquarium, you will then have several purchasing solutions: a fully equipped aquarium with a lighting gallery and accessories (filters, heating, etc.), an aquarium with a lighting gallery only, or a bare glass pan.

Aquarium Guide For Beginner:

For the beginner aquarist, I recommend the fully-equipped aquarium to become familiar with the equipment. For the confirmed person, an aquarium and lighting gallery will be more suitable, because they can adapt their accessories to their needs. Finally, for DIY enthusiasts and aquarium enthusiasts, a glass tank may be the best solution.

Killifish, regardless of their variety, are large fish that need swimming space. Your aquarium must be at least 30 to 40cm high. The longer it will be, the better it will be for your fish, 80cm minimum. This will allow them to swim more freely, their muscles will work, and their health will be even better. Bonded glass aquariums are the strongest and most widely used.

To start well, I recommend a 100-liter aquarium with 2 small Killifish (less than 10cm, without the tail). The larger an aquarium, the easier it is to maintain and the more comfortable it to achieve biological balance in the aquarium. You will have more problems with small volumes of water.

So you’re going to tell me: aquariums are expensive, and I don’t have the space to take a big one. And I would answer you that you should not start the aquarium hobby, because, like any passion, it has a financial cost, but no more than another, especially if you start with a good foundation.

When instead, yes, a Killifish aquarium takes up space, so if you cannot have an aquarium of at least 100 liters in your home, go to the Nano-aquariums that can accommodate other species of fish.

How to calculate the gross volume of an aquarium?

Volume = Length x width x height ÷ 1000 (Example: 81cm x 36cm x 50cm ÷ 1000 = 145 liters)

Aquarium Killifish Setup

The brands and models mentioned are used to guide you through the multitude of accessories and manufacturers. I recommend them to you for having tested them and for using them daily. Be careful, we do not take the fish at the same time as the equipment; the aquarium needs to be run in for 4 weeks before the introduction of the fish.

  • Aquarium of 100 minimum, equipped with light and filter
  • Strip test pack (example: JBL Test 6in1 )
  • The dose of bacteria to start your screen (example: Tetra SafeStart )
  • Bag of approximately 10 liters of gravel (example: JBL Manado )
  • Manual siphon
  • Magnet for windows
  • landing net, fine mesh
  • Box of food, in granules (case: Tetra Killifish  Japan )
  • Anubia barteri (plant)
  • Java fern (plant)
  • Cladophora (plant)
  • Small mangrove roots

Selected plants do not require additional fertilizer at the bottom of the aquarium; they attach themselves to the roots. For very tight budgets think of second-hand aquariums, you can find 100 liters for not too expensive, and close to home, on the sites of free online classifieds.

aquarium for killifish

How to breed killifish?

For top hatchery, a 1/2 inch layer of prospective peat at the bottom of the brooder makes the water acidic. Also, it gives a dark base for these fish to use. The peat will be squeezed for five minutes and then will be allowed to extract from the peat.

The peat should be around a specific tail for bottom spawners to include a slow depth for spawning. Remember, these species must have the illusion that they are burying their eggs deep enough to hear the drought to come. When spawning, it is best to put one male with three females as males are tough conductors. The males are easy to recognize as they have a lyre-shaped tail in many species and are much more colorful than the females.

The hatching of perch takes about three weeks, while the eggs of the lower broodstock (depending on the species) have to be kept in moist peat for about three months before the water returns to the container. It is possible to experience the miracle of the killifish life cycle, compensate you for buying eggs from online breeders. These eggs come in moist peat and are already correctly aged.

That is, add what you know, what you know, and what you need to do. This is a cheaper, more natural way to own a dead fish collection than to buy traditional fish. Because these are so short in time, you can experience them for an initial period.

Killifish Care Guide

Insertion of the Killifish in New Tank

Place the closed transport bag gently in the aquarium for about 20 minutes. This is how you ensure temperature compensation. The higher the temperature differences in the bag and aquarium, the longer you should wait.

Now carefully open the bag at the top and gradually add water from the aquarium (approx. Every 10 minutes) so that the water values ​​adjust and the killifish can slowly get used to it. Now you can release the killifish from the bag into their new realm. To do this, carefully lift the killifish out with a net.

Replace the Tank for Killifish:

Did you get a Killifish as a gift, or did you win one at a party? The first instinct was to take a jar or a pseudo aquarium of about 20 liters? It’s a bad start, but luckily you can fix it quickly. If you are a minor, your parents will have to be convinced to invest in an aquarium. The best way to inform them is to have them read our articles.

If the purchase of an aquarium is still not possible, the best will be to separate yourself from your Killifish for its well-being. If the purchase of an aquarium is potential (available space + budget), it’s perfect. For small budgets, think of second-hand aquariums. Sometimes the decision-makers (the parents) only agree for an average size aquarium of 50 to 60 liters; even if it is little, it will always be preferable to the jar. Also, an aquarium of this liter allows you to have effective filtration.

PH of the Aquarium:

You should consider adding a natural element to lower the ph. Almond / Indian oak leaves slowly release tannins as they add driftwood, lowering the ph. If you have a planted tank, you can start injecting CO2, which will also reduce the ph. Another possibility is to filter the water through peat or commercially available peat granules.

Check all your stones – several, like B. B. The limestone contains enough calcium to keep its pH high. The usual “vinegar test” is to determine if the rock is bubbling when it comes in contact with a drop of acidic vinegar or, ideally, more. If so, it affects your pH.

That said, don’t worry too much if you can’t get it super low. Don’t assume that every fish you see on your LFS will adapt to your water, but many fish, as long as you are regularly serviced. Some of the most common commercially available fish are bred domestically underwater conditions that are not what they “should” be on paper.

Get it as close as possible, but I would avoid taking drastic measures, especially anything you would keep adding. If your tap water and tank condition are at a slightly high steady-state pH, it will be easier for your fish to adjust to it than if the pH keeps going up and down.

Related. Best Water for Aquarium.

Killifish Species

Killifish Species Feeding

We have put together some necessary information and tips on killifish feeding below:

  • Select species-appropriate feed, the composition of which is tailored to the needs of the different killifish (e.g., in the form of flakes, granules, tablets, jelly, etc.).
  • Feed only as much as the killifish can eat within the next few minutes, leftover can affect the water quality. The food should be consumed entirely in 2 to 3 minutes.
  • Food tablets for bottom killifish may last a little longer. Food that has not been eaten rots in the aquarium and provides algae with an optimal breeding ground. The biological balance can thus be damaged in the long term and, last but not least, the killifish are in mortal danger.
  • As with us humans, improper killifish nutrition leads to health problems. Obesity, organ damage, and organ failure can result. Some killifish are beggars, and especially beginners are tempted to give too much food. Killifish are very energy-saving creatures.
  • One day of fasting a week is good for the killifish because, unlike their natural environment, they are served the food in the aquarium on a silver platter, except for fry. These should be fed several times a day.
  • Since the aquarium water is most polluted by killifish excretions, it is essential to choose a high-quality feed that the killifish can optimally utilize.

Tailored Feed:

As different as the species of killifish in a tropical aquarium, their needs are usually as different. Killifish feed either on the surface, in the middle, or on the bottom of the aquarium.

You can often tell from the mouth shape of your killifish their feeding preferences:

Mouth shape Types of food Ingestion
subordinate Flakes, crisps, sticks, dried natural food on the water surface
terminal Flakes, granules, gel feed, crisps in the middle
subordinate Flakes, granules, crisps, tablets, wafers, gel feed on the ground

What Do Killifish Eat?

To ensure that your killifish are adequately fed, You should consider the respective eating habits when choosing the food. If you tend to keep shy animals together with more knowledgeable killifish, it is advisable to use small tricks when feeding. With certain types of feed, weaker killifish are also used.


Flakes are ideal for killifish in all water zones. They can be fed both on the water surface and during the sinking. The fine grinding ensures a quick soak in the water, and the nutrients can be easily used.


Granules are very porous. They, therefore, soften extremely quickly and slowly float to the bottom of the aquarium. As a result, they can soon be eaten by shy, smaller killifish.


Crisps are perfect for filling automatic feeders so that killifish are well taken care of when you are not there. This type of feed usually contains more energy than conventional flake food.


Tablets are suitable for all ornamental killifish that live close to the bottom, for example, killifish, loach, or founding barbel. This form of feed immediately sinks to the bottom. It disintegrates there so that the place of feed can be accurately determined, and shy killifish can also eat.

Natural Food:

Red mosquito larvae, daphnia, brine shrimp, or krill are suitable as additional food. Such dried food animals float on the surface of the water. They are, therefore, a treat for labyrinth killifish and livebearers.

Gel Food:

This type of food is intended as the leading food. It is strictly based on the natural eating behavior of the killifish. It is mostly enriched with trace elements, vitamins, proteins, and fats.

Essential nutrients in killifish feed:

The majority of the commonly kept killifish species are omnivores, who are always on the lookout for varied animal and vegetable food. Small crustaceans, worms, mollusks, plants, and algae are on their daily menu in their natural environment. There are also herbivores and carnivores.

When formulating killifish feed, care must be taken to ensure a balanced and correct composition of all nutrients

Nutritions for Killifish Species

Nutrient group function
Proteins Indispensable building blocks for the formation of tissue and thus for growth
Fats Most important energy reserve and essential for the formation of body cells.
Vitamins Support the immune system and metabolism
carbohydrates Main energy supplier
Dietary fiber Promote digestion
Minerals Building materials for skeleton and muscles, beneficial for all bodily functions

New Killifish Buying Guide

Before you use the killifish, you should consider the “running-in time” of the aquarium from 3 to 4 weeks! Be sure to do a water test before inserting the killifish!

After you have received new killifish in a transport bag, you should make sure that they are transported without much vibration and not for too long. The longer the transport route, the more air or oxygen there should be in the bag – clarify the amount in advance when buying!

When buying, make sure that the killifish species have different swimming areas, i.e., like to swim on the water surface or in deeper climes – this brings life to the booth!

Also, you should not “overpopulate” the aquarium. Start with a few types of killifish, especially as a beginner. You should buy new groups of killifish every two weeks so that the individual groups can acclimatize to their new home in peace before new residents arrive. Every peace-loving killifish should have at least 2 to 3 liters of water in the aquarium per cm of its size.

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