Not all fish are suitable for beginners. There are many freshwater fish that should be avoided by beginners. Although commonly sold at pet stores, it’s a bad idea for beginners to take care of these fish. They require special conditions that makes it challenging for beginners to tackle. For example, some of these fish are sensitive to even the slightest fluctuations of water quality. While other species may need special brackish or softer water parameters. Some freshwater fish are aggressive and can grow rather large which can become too challenging for beginners. While others are not good community fish, they may seem harmless as a juveniles but can quickly become a major predator in a beginner’s aquarium! Here are 12 freshwater fish beginners should avoid.
12 Freshwater Fish that Should be Avoided by Beginners
1. Red Devil (Amphilophus labiatus)
Red Devil is a freshwater fish that beginners should avoid. It is an extremely aggressive and territorial fish. It’s definitely not a good tankmate in community aquariums because it will eat up everything! Red Devil cichlids can only be mixed with other tough fish. I don’t recommend Red Devil cichlids for beginners (and non-beginners)!
|Red Devil Cichlid|
|Problem for Beginners||Extremely aggressive|
2. Rummy Nose Tetra (Hemigrammus bleheri)
Rummy Nose tetra is a freshwater fish that beginners should avoid. They are very sensitive to water quality conditions. Nitrate buildup can cause stress and can kill your Rummy Nose tetra. It’s best to avoid taking care of rummy nose tetras if you are new to fishkeeping.
|Rummy Nose Tetra|
|Problem for Beginners||Highly Sensitive to Water Quality|
3. Tinfoil Barb (Barbonymus schwanenfeldii)
Tinfoil Barbs should be avoided by beginners. They are commonly sold at pet stores as small juveniles and often kept in community tanks. However, the beginner aquarist may not realize that each fish in the school of juvenile Tinfoil Barbs can grow up to 14 inches long! They will quickly outgrow the beginners community tank! You will need a really large aquarium if you want to keep Tinfoil Barbs. It’s not realistic for beginners and non-beginner aquarist to care for Tinfoil Barbs.
|Problem for Beginners||Can Grow Really Big|
4. Jewel Cichlid (Hemichromis bimaculatus)
Jewel Cichlids are freshwater fish that beginner should avoid. They are extremely aggressive when breeding and will be too much to handle for the beginner.
|Problem for Beginners||Extremely aggressive when breeding|
5. Jack Dempsey (Cichlasoma octofasciatum)
Jack Dempsey is a freshwater fish beginners should avoid. It is a type of cichlid that can grow quite large up to 8 inches long. It is commonly sold in pet stores as part of a mixed cichlids variety. Beware, Jack Dempsey can get aggressive and will bully other fish if kept in a community tank. If you want a Jack Dempsey, keep it in a species only aquarium or with other large, tough cichlids.
|Problem for Beginners||Gets too big and too aggressive|
6. Blue Discus (Symphysodon aequifasciatus)
Blue Discus fish should be avoided by beginners. It is difficult for beginners to get the water parameters right because discus require soft, acidic water. Soft, acidic water is also not compatible with water requirements of most community fish. If you want to keep discus, you should house them in a species only aquarium. Although peaceful, Blue Discus can get very territorial when breeding. I recommend beginner fishkeepers to avoid Blue Discus and other discus because they can be challenging for beginners.
|Problem for Beginners||Requires soft, acidic water. Aggressive when breeding.|
7. Sucking Loach (Gyrinocheilus aymonieri)
Sucking Loaches are freshwater fish that beginners should avoid. They are sold as juveniles and often added into community tanks as a bottom-dweller, algae-eater fish. However, Sucking Loaches can grow really big, up to 11 inches long! They are also very territorial and aggressive towards tankmates. Sucking Loaches can become a problem for the beginner fishkeeper.
|Problem for Beginners||Grows Really Big. Aggressive and Territorial.|
8. Red Snakehead (Channa micropeltes)
Red Snakeheads should be avoided by beginners. They are sold as small juveniles but can grow really big to 39 inches long! Red Snakeheads are carnivores and if kept in a community tank will soon eat up all the tankmates!
|Problem for Beginners||Grows Really Big. Aggressive Carnivore.|
9. Mudskipper (Periophthalmus barbarus)
Mudskippers should be avoided by beginners. Mudskipper require brackish water which is very difficult for beginners to maintain. It is also territorial which can be challenging for beginners.
|Problem for Beginners||Requires Brackish Water. Territorial.|
10. Clown Knifefish (Chitala chitala)
Clown Knifefish is a freshwater fish that beginners should avoid. They are small as juveniles but they can grow really big- up to 39 inches long! If put in a community tank, the Clown Knifefish will get too large. It is also very aggressive which is bad news for its tankmate!
|Problem for Beginners||Grows too Big. Agressive.|
11. Arowana (Osteoglossum bicirrhosum)
Arowanas should be avoided by beginners. Arowana can grow really large- up to 47 inches long! They are carnivores and will require live food. They are definitely not a good community fish as they will end up growing too large and eating up all the tankmates! Arowanas are considered lucky for many Asian fishkeepers but its not easy to care for so beginners should avoid it.
|Problem for Beginners||Grows too Big. Carnivore predator.|
12. Oscar (Astronotus ocellatus)
Oscars are popular freshwater fish, however if you are an absolute beginner, you should avoid Oscar as your first fish. First of all, Oscars can grow really large- up to 13 inches long. They are sold as juveniles and often times, pet stores don’t disclose how big they get as adults. Oscars are carnivores so if you put them in your community tank, your Oscar will eat up all the smaller tankmates. I do love Oscars because of their puppy-like personalities. Once you gain fishkeeping experience, go ahead and get an Oscar. Keep your Oscar in a large, dedicated aquarium that is at least 50 gallons.
|Problem for Beginners||Grows too Big|
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