Best & Worst Fish For FishKeepers 
If you know too little about the fishkeeping hobby, it’s better to get an easy-going pet for your home aquarium.
If not, you’ll end up making the biggest mistake of your life.
So up next in this post, I’ll list one of the Best and worst beginner fish. Let’s get started:
I love Neon rainbowfish or also known as the dwarf or praecox rainbowfish. This species offers all the benefits of neon tetras without the negatives. Two-inch dwarf rainbowfish. Calm shoaling fish, they should be kept in groups of five or six. It may seem like a lot, but seeing a school of rainbowfish interact is far more satisfying than watching one nervously dart about the tank.
Full-grown specimens rival neons in color splendor. If you take care of your fish, you can grow a gorgeous blue body with red or yellowfins, even if they look dull in stores. Male fish struggle and display their red fins to attract females. The dwarf rainbowfish’s behavior and mature color fascinate me.
They’re also tougher than neons. Despite preferring alkaline water, they can’t survive in acidic water. Better tolerate water quality and chemistry changes. If you replace the water regularly, they should be fine. They’re harder to find but worth it. I’ve seen these in pet stores. I recommend neon rainbowfish as an alternative to neon tetra for beginners.
Several tetras are good for beginners. Black skirts, bloodfins, glowlights, serpae, and x-ray tetras are neons’ hardier cousins. Learn whether any of these creatures interest you by doing research. These species are hardy and easily available in fish shops. You should have at least five or six of them in your tank because they congregate in huge numbers.
Anglers love the enormous, predatory oscar. Because of their predatory nature, Oscar tank mates can become your biggest worry as an oscar fish would eat them up.
An oscar fish is 18 inches long and bulky and their size is the biggest reason why many can’t find a big enough tank. Even a 55-gallon tank can find it difficult to hold an oscar fish. Then if you’ve decided to keep them, you must make weekly water changes and keep the aquarium fish-free. Due to their size and messiness, Oscars need tanks greater than 75 gallons.
They also get “hole-in-the-head,” a difficult-to-treat condition. Large sores occur on the fish’s head and lateral line, perhaps killing it. Poor Oscar water quality is suspected. If the water isn’t changed often enough, it can poison fish.
Oscar feeder fish can introduce various diseases to the tank. I don’t recommend using feeder fish until absolutely essential. Make sure the fish aren’t infected before adding them to Oscar or your main tank.
Finally, locating fish suitable for Oscars is difficult. Due to their large mouths, keep them with similar-sized fish. Oscars are territorial and avoid conflict. They’ll target other cichlids they perceive as a threat, but larger, more aggressive members of the species will also target them. This requires a huge tank for the oscars and other fish. Many newcomers wish to have more than one Oscar in their tank, but this is tough to achieve.
Oscars, like their relatives, should be kept in large aquariums (hundreds of gallons). Each fish’s individuality and social structure provide you with a look into their life. Oscars and other huge cichlids should be left to experts who can properly care for them.