Top 5 Easy Fish Breeding Ideas for Your Next 20-Gallon Aquarium

When our founder Cory first got into fishkeeping, funds were tight, so he started breeding fish to help with his hobby expenses. After many years of experience keeping fish rooms and tanks of all sizes, he still loves breeding fish at home in the versatile 20-gallon aquarium (both the high and long versions). Find out his 5 top favorite fish and invertebrates to spawn and raise in a colony setting.

1. Mouth-Brooding Bettas

Betta albimarginata

Most people know about Betta splendens with their large and colorful fins, but breeding them can be hassle since the male juveniles are too territorial to cohabitate and must be raised in individual jars until they reach a sellable size. Some mouth-brooding Betta species, however, are more peaceful and can be kept together in 20-gallon breeding sets. We have personally kept and had great success with strawberry bettas (B. albimarginata and Penang bettas) but there are other species like snakehead bettas and B. rubra. To break up the line of sight and create hiding places for future fry, we like to plant the aquarium densely and add tall hardscape. A tight-fitting lid is recommended to increase humidity and prevent fish from jumping out. For aggression-free swimming, small dither fish can be added to the tank such as neon Tetras. These bettas love acidic, tannin-stained waters so make sure to include catappa leaves and other botanicals.

After the eggs are fertilized and the female has borne their offspring, the male must keep the brood alive for the next 1.5-3 months. After the babies are born and have begun swimming freely, the male will dispose of them and leave them to fend for their own good. Baby brine shrimp is a superfood that can help fry grow quickly and powerfully. Just know that the male cannot eat while he is holding eggs, so to prevent him from losing too much weight, put the female into a separate tank or breeder box until he has time to regain his mass before breeding them again. The juveniles should be removed from the tank as they become more crowded. This will prevent territorial disputes and make the tank more spacious.

2. Dwarf Shrimp

Neocaridina davidi

If you want to breed something that’s in high demand and easy to sell, then dwarf shrimp are the way to go. There are many species to choose from – such as Neocaridina cherry shrimp, Caridina crystal shrimp, and even Sulawesi shrimp – so select a type that works best with your normal tap water’s parameters. Dwarf shrimp love to eat all the gunk and mulm in an aquarium. They do well in a tank that has been in good condition for several months. Although it is nice to have them in a planted aquascape, they will be happy eating the algae-filled food. Use a sponge filter that has gentle flow or put a prefilter sponge on your canister filter to keep any babies from getting sucked up.

If your goal is to produce as many shrimp as possible, then keep a species-only aquarium with no other tank mates. If you are looking for a more lively aquarium, you can add nano fish such as chili rasboras or green neon tetras. They will be more likely to eat the colony, and they will also need to be fed heavily to provide safe places for baby shrimp to escape. For more ideas, read our article on the top 12 tank mates to keep with dwarf shrimp.

3. Fancy Guppies

Poecilia reticulata

Another aquatic animal that is super popular and easy to breed is fancy guppies. Like most livebearers, just provide good water and food and they’ll reproduce like rabbits. If the parents are not available to care for their children, you can add more plants, such as Pogostemon Stellatus ‘octopus’ and water sprite, so that the babies have cover and the adults can reach them. Either you want to breed a tank with random colors or a single pure color. You should prepare to cull any fry that have deformities or other undesirable characteristics. This will make it easier for you to improve your line breeding efforts. Read the entire article for more information on colony breeding livebearers, such as guppies.

4. White Cloud Mountain Minnows

Tanichthys albonubes

Hobbyists tend to think that egg layers are more difficult to raise than livebearers. White cloud minnows, however, can be a great way to start if you have never tried it. Because they are sold as feeder fish, Cory originally bought a group of them for cheap and then was surprised when he accidentally bred a ton of them. His success encouraged him to start the “White Cloud Race” at the local fish club. Contestants would start with six mininows and see how many can they make in the summer season. This beginner-friendly fish is quite hardy and can even be kept outside in mini ponds during the warmer months. As long as you don’t have too many snails or other fish with them, the fry can be raised up with the adults in the same colony. It’s the older juveniles that will sometimes prey on their younger siblings, so add plenty of dense, fluffy plants for shelter and keep moving out the teenagers to increase the fry survival rate. To learn more about their husbandry and the different color variants, read our care guide.

5. Desert Gobies

Chlamydogobius eremius

You might feel like you know how to breed all the most common fish species after years of fishkeeping. Is there an oddball fish you can find that is easy to reproduce? Meet the desert goby. Although it isn’t the most colorful fish, we love their unique appearance and unusual behaviors. They can be kept in community aquariums, but the majority of them will end up being food. Therefore, we prefer to keep them in a specific species-only facility for breeding. Their large mouths can make them territorial and they will need lots of hiding places during the spawning season. To encourage breeding, add a 0.5-inch (1.3 cm) PVC pipe and watch them lay eggs inside. You’ll see little fry crawling around the ground once they hatch. They don’t yield as many eggs as livebearers and won’t be able to grow large colonies. However, they are an interesting fish that many people have never tried.

Best of luck with your next 20-gallon breeding project. Although we do not ship live fish, you may browse our stocking lists at the preferred online retailers to view what they have. Check out our top articles about breeding aquarium fish for more information.