Today I would like to deal with a slightly different topic. Many of us fishermen have a pond or aquarium at home and what could be more natural than to stock an aquarium or pond with native fish to study their behaviour. Personally I never liked guppies and co. as much as “real fish”, i.e. pike, zander, perch or carp. However, their keeping is not easy, especially not in an aquarium, even with small bait fish it is not so easy. Here are some tips what you should know about this topic.
Already as a child I had a 100 l aquarium (My recommendation: Good aquarium complete sets with test reports) with two veiltails and a real small mirror carp, but of course this only worked for one season, because the carp grew fast. Since then it lives on in the garden pond and has grown to a stately size. At the moment I have a pond as well as some aquariums with not exactly classic fish, namely tilapias this is one of the most bred aquaculture fish because of its robustness, fast growth and resistance to stress and handling. These fish are very popular especially in aquaponic systems and present me with similar challenges as native fish.
It’s great to watch fish in their element and to see them hunting for prey or even small animals. Even the food intake of worms can be informative and answer some questions for us anglers. So the whole thing is a very exciting topic and aquaristics is an exciting hobby.
Release native fish species
Many native fish grow quite large and grow out of the tank quickly unless you have a 10,000 liter tank. Of course fish must never be released into natural waters or fishing waters. Because this is forbidden for good reason, as every angler should know. This can lead to the spread of diseases and even neozoans, i.e. non-native fish, can spread and change our water ecosystems and displace native species. An example of this is the sunfish, a popular aquarium fish, which now lives in many German waters where it has no place and is reproducing rapidly. The release of American crabs by aquarium keepers has also led to the transmission of the crayfish plague and the destruction of the noble crayfish stocks in Germany
These native fish can be kept in an aquarium
Generally, with an appropriate tank size, almost all fish can be kept in an aquarium, but it sometimes requires a lot of know-how, because water quality, tank size and above all type of food and quality are important. I know a few anglers who have had a small pike or zander in an aquarium at one time, but it is quite difficult to get food, because a zander does not accept pelleted food from the shop, especially if they are small. Equally choosy are perches, whose keeping is not exactly easy. Although they can be re-accustomed, this is rather something for professionals in aquaculture or large aquariums such as zoos or sea life. Salmonids should also be avoided, as they are extremely sensitive to high temperatures and nitrogen compounds (ammonium, nitrite and nitrate) in the water. With a continuous flow system this can also be realized, but trout and Co. are extremely sensitive fish.
Species that are protected are also taboo as long as they are not from a pet shop. Also not every small fish can be kept well in an aquarium: For example, arbours need a lot of space and are difficult to keep. Nevertheless, some native species can be kept very well in an aquarium, even permanently.
In general almost all pond fish, which are also available in pet shops, can be kept well in an aquarium. As already mentioned carp can also be kept in an aquarium but only up to a size of 20-30 cm in an aquarium of at least 500 liters.
What you need for an aquarium with native fish
For an aquarium with native fish you can save some things like a heater. Nevertheless, it needs some technology and also some equipment.
- An aquarium with at least 80 l, how to do that is explained below
- A filter
- Ground, like gravel
- Hiding places like roots and stones
- Some water plants
- A cleaning crew of snails
- Aquarium food
Let the aquarium run in correctly
Before you can put fish in an aquarium, you should let it run in for at least 14 days with the filter switched on. This ensures that the important bacteria can form, which convert the toxic metabolic products (excrements) of the fish into less toxic ones. You can speed up the process a little by adding live bacteria or some pond sludge, but you can also catch all sorts of unwanted animals. It is better, for example, to use a few pond snails, which you feed with flake food and thus promote the growth of the natural and useful bacteria
Maintenance of an aquarium
Besides feeding, an aquarium needs a lot of care. The most important is probably a regular water change of about 10-20% of the water volume weekly. It is important that the fresh water has a similar temperature as the aquarium water. Many fish do not tolerate rapid temperature changes well. Otherwise you have to clean the filter regularly. It is best to do this with the water that you have drained from the aquarium. This is best for the bacteria that have settled in the filter sponge or medium.
My tip is to use an aquarium filter as large as possible, preferably an external filter from e.g. Eheim and rather oversize than undersize. This saves time and gives the tank more stability. It is also important never to overfeed the fish or use too many fish. Otherwise you will have to change water more often and invest more time in maintenance.
What is your experience with native fish in the aquarium ? Just write me a comment. You can also ask me questions about aquariums, technology and filters, as I am an experienced aquarist.