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The Best Intermediate-Level Freshwater Fish


I have had pets all my life, and proper pet care is super important to me.

Intermediate fish require a bit more care than fish for beginners, and many of them are quite beautiful! This is a moonlight gourami.

Intermediate fish require a bit more care than fish for beginners, and many of them are quite beautiful! This is a moonlight gourami.

If you have been keeping aquariums for a couple of years, you may want to move up to more intermediate-level freshwater fish. Intermediate fish require more specialized care than our beginner fish friends. However, some of the intermediate fish listed are the most colorful and unique fish out there.

If you feel you are ready for a little more challenge in your aquarium, intermediate is the next step up. Check out some of the coolest intermediate fish and learn how to properly care for them.

  1. Cichlids
  2. Bichirs
  3. Plecos
  4. Mollies
  5. Gouramis


Cichlids, whether African or South American, are widely considered one of the most beautiful freshwater fish for aquariums. This is because they come in a wide variety of bright colors and patterns. However, cichlids usually do best in a species aquarium, where they live with only other cichlids. Cichlids may even fight with each other, which is why it is best to avoid getting similar-looking cichlids for your tank.

Cichlids need some specialized care as well. They prefer a higher PH than most other fish. They can also get big depending on what kind you get, so you will need to have a large aquarium to house a sufficient group of cichlids. 50 to 75 gallons is a good minimum.



Bichirs are long fish that almost resemble eels. They can get very large—over 10”. This means you need to have a large enough aquarium to house them. Anything under 50 gallons is probably too small. Some species of Bichir are simply not appropriate for home aquariums. Remember that these fish are bottom-dwellers, so you will need to have a lot of space at the bottom for them to swim around in. A long aquarium is better than a tall aquarium for this species.

Bichirs will escape any aquarium without a very tight-fitting lid. They are also carnivores, and they're predators in the wild. They will eat any fish they can fit in their mouth. For this reason, their tankmates must be carefully selected. Large, peaceful fish are the best option.



Plecos, or Plecostomus, are a type of bottom-dwelling, algae-eating fish. Unfortunately, these fish are often sold to beginners under the guise of being a tank cleaner. The truth is that these fish, while they are algae eaters, are very messy. They make a lot of poo in a tank, so they can really increase the bio load. More water changes will be required if their poop raises the ammonia to dangerous levels.

Another important thing about plecos is that they are not small fish. Plecos can get to over 12” long. Beginners will often get them for a 10 or 20 gallon tank, but the pleco will quickly outgrow this. A tank of 100 gallons is really necessary to handle their size and bio load. 50 gallons may be acceptable for the smaller pleco varieties.



Mollies are cute fish that are well-suited for community aquariums since they are peaceful. They come in a wide variety of colors and patterns, including gold, spotted, and white. Mollies don’t need to school, but they do like the company of other peaceful fish. The reason mollies can be considered intermediate is because they are typically brackish water fish. This means they like some salt in their water. However, mollies will typically adjust to no salt or a complete saltwater tank.

Mollies are live-bearers, so if you have a group of mollies, you’ll likely end up with babies. If you don’t want to deal with fry, the fish will usually eat them if they are hungry. You can also get a fish for the tank that will be likely to eat fry. Of course, you can also try to raise the babies if you have enough room for more mollies!



Gouramis are another fish that is well-suited for a community aquarium. They are bigger fish that are very peaceful to most other fish. However, they can be aggressive to similar species, such as angelfish, betta fish, and other gouramis. This is why it can be best to have one gourami as the centerpiece of a community aquarium.

Gouramis are like betta fish; they breathe water from the surface. Gourami fish come in some very cool colors and patterns, and they can make a striking addition to any aquarium. Remember that gourami fish can get up to several inches, so an aquarium of at least 20 to 30 gallons is best for one fish.

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