The Beginner Guide to Fish Breeding
Updated: Apr 10
Once you’ve got an aquarium set up and you’ve mastered how to keep levels in check, plants at bay and your fish happy and healthy, you might next turn your aquarium adventures to breeding fish! Anyone in the aquarium hobby will be able to enjoy seeing a pair of their fish mate, produce fry and then be able to raise the fry to maturity. There’s not many better feelings of accomplishment you can get from keeping fish than raising a couple of generations, and as a bonus, it allows you to share your new fish with other aquarium hobbyists.
Let’s start with the time of the year - which months are best for breeding?
Well it’s an easy answer - any really! In the wild most fish will breed during the spring. They go through the dullness of winter and have less light during the day as well as lower temperatures. As the water warms up in spring and the days last longer they know that good conditions are ahead and that it’s safe to breed. In captivity, we can control this ourselves! You can replicate this at home by doing more frequent water changes and increasing the temperature slowly on the thermometer, as well as gradually increasing the length of time that the lights stay on.
By creating an environment in your tanks that's as close as you can get to their natural environment, whilst also providing more food that’s more protein based then you can condition your fish to reproduce. Different species of fish lay eggs in different ways, so there's several aquarium set ups, plant types, breeding surfaces and foods that are focussed on stimulating spawning for certain types of species. Search online for your specific type of fish to learn what equipment and environment you’ll need.
What size breeding tank do I need?
We find that the 10-gallon aquarium is both inexpensive, easy to store, easy to get supplies for and is enough room for you to breed almost any beginner fish species. As you get deeper into the hobby you may need taller tanks for depth or longer tanks for fish whose breeding habits require them to run at high speeds. A common 10-gallon aquarium, with an air pump, a sponge filter, a heater of sufficient wattage and a good lighting system will both do the trick and not break the bank.
The bonus is that a 10-gallon aquarium is big enough to keep fish in, raise the fry, or, when the project is over, store easily in a closet with all its supplies tucked neatly inside as if it were its own box.
Which fish are good options for beginner breeding?
The easiest egg-laying fish to start with are egg scatterers like the zebra danio and rosy barb, and substrate spawners like convict cichlids and firemouth cichlids. Many other species lay their eggs in various ways, including mouthbrooders that carry the eggs and even babies in their mouths, but it is best to start with the basics until you are comfortable with the care of baby fish.
For tropical fish, what should I look for in a breeding pair?
You’ll want to identify the best colour, size and vigor of the fish. When you’re shopping for breeding fish though this is one part of the process that is time dependent. Tropical fish are usually bred in southeast asia and American states such as Florida and typically they’re forced to breed in the spring in indoor aquariums. Then, the baby fish (fry) are placed into outdoor ponds and they grow to size there while they’re fed live food for the fry, then pellet foods as they grow larger. By the time they’ve grown fully it's around the autumn time, so by shopping around winter time for your breeding pair you’re more likely to find a great breeding pair right at your local pet store.
Once you’ve identified the pair you want to breed, make sure they’re alone in a tank. That means either just buying two from the get go or providing them with their own tank away from your original community. They’ll need an appropriate spawning decor which is dependent on that species’ method of egg laying. Provide them with high protein foods, typically 3 times a day. This feeding boost will give them sufficient energy in their bodies for their own maintenance and growth as well as energy for breeding and creating eggs. Feed both the male and the female live brine shrimp if possible. If that is not available, frozen will do. We have a DIY Brine Shrimp Hatchery guide you can follow here, to make sure you have a constant supply.
For some species, separating the males from the females by using a glass partition so that they are still in view of each other at all times, but cannot physically get to each other, increases the need to breed when given the chance. During this period of conditioning, raise the temperature to about 78-82 degrees F, depending on species, which is warmer than your community aquarium usually is kept.
All these things being done together will cause the female to become loaded with roe, or eggs. During this period of conditioning, it is also important to bring the pH, water hardness and alkalinity to the levels prescribed for the breeding of that species, if this is an important factor for their reproduction.
What about the pH Levels?
The pH value is the acidity/base balance of the water, which can be readily determined by test kits and strips offered for sale in Aquarium Stores. It is generally understood that a somewhat acid condition in the water of the aquarium is rather desirable for most fish species. However, some fish, such as African cichlids, may prefer a basic (higher pH) water. Check aquarium fish websites and fish breeding books for the exact water conditions preferred by the species of fish you are attempting to breed. The pH of the water can be adjusted to meet the needs of your fish species by adding pH adjusting products available from your local fish store.
One of the hardest parts of breeding egg-laying fish is supplying the newly hatched fry with food small enough for them to eat so they survive and thrive. The majority of aquarists favor the use of infusoria as the first food for their fry. Infusoria refers to many small organisms in the water that tiny fry can feed upon, including bacteria, protozoa, algae, and tiny crustacea.
To grow infusoria, place a lettuce leaf in the spawning tank as soon as the adult fish spawn. The leaf will decompose and create sufficient infusoria for the first week or so, at which time the old leaf can be removed and another leaf can be added, to be followed a week later by feeding any of the finely powdered prepared foods for sale in the aquarium store, or commercial paste food preparations such as Liquifry.
Later on, the fry may be fed the yolk of a hardboiled egg mixed with a little water into a paste and added to the tank. Make sure you place this near the fry as they may not be able to swim very far yet. As the fry grow, tubifex worms and flake fish food ground up between your fingers may be added to the diet. Remember, with fry the most important thing is to keep their bellies full at all times. This means feeding young fish at least 6 times per day. You can quickly starve fry to death if you miss even one day of feeding.
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