Hardy Tropical Freshwater Fish for New Tank (Aquarium)
By Eddie Waithaka @aquariawise

When selecting fish for a new tank, it is crucial to choose hardy fish that can withstand the stress of being introduced to a new environment.
Whether you want a fish that can survive fish-in cycling, newbie-mistakes can feed on varied fish foods, cope in cold or heated tanks, and various water parameters and quality…
Below are the fish I recommend you go for!
- Danios (Zebra, Giant, Celestial pearl)
- White cloud minnow (Gold, Standard)
- Platies (Good starter fish, look spectacular on a dark background, but they breed a lot, so keep that in mind.)
- Mollies (Perfect hardy fish. If you add male and female, you will have hundreds soon.)
- Guppies (Hardy, colorful fish. If you add male and female, you will have hundreds in a month or two)
- Rasboras (Chilli, Phoenix, Strawberry, Dwarf emerald)
- Otonciclus Catfish (tiny bottom feeder, ideal for nano tanks. Great algae-eaters)
- Clown Loach (are great bottom feeders)
- Cories (Pygmy, Habrosus)
- Bristlenose Pleco (Docile with an incredible range of livable conditions)
- Gourami (Dwarf, Honey, Sparkling, Betta)
- Fancy Goldfish (Readily available, many varieties, and will survive in cold water. However, they have a big bioload and are not ideal for small, beginner tanks)
- Endler’s Livebearer
- Rice fish
- Vietnamese Cardinal Minnows
- Shrimp (Cherry, Ghost)
- Mosquito fish
- Climbing Pearch
- Kribensis ( Awesome little cichlids that don’t get big and are generally somewhat peaceful.)
- Angelfish (Beautiful fish with unique features, but can be aggressive and require a high (than long )because of their fins.)
- African cichlids
- Central American Cichlids
- Red Zebra African Cichlids
- Bichirs
- Tetras (Platinum, Neon, Embers, Bucktooth, black skirt)
- Kuhli loach
Ensure you research the fish you want to keep so you don’t have any incompatibilities. Things to look out for: size, water temperature, PH, hardness, and aggressiveness.
What is A Hardy Aquarium Fish
A hardy aquarium fish is a fish species that can tolerate a wide range of water conditions and is relatively easy to care for in an aquarium setting.
Hardy fish can be ideal for beginners or those looking for low-maintenance aquatic pets. They are also perfect for fish-in cycling.
Hardy tropical fish, like danios, tetras, guppies, and cories, are known to adapt to different water conditions and are less susceptible to diseases and stress compared to other species.
However, it’s important to note that all fish require proper care and attention to thrive in an aquarium environment, even hardy fish, like danios and livebearers.
Focus on your nitrogen cycle and set up a habitat tailored to the fish you want, and you’ll be more successful.
What is The Most Hardy Aquarium Fish
Zebra danios are arguably the hardiest aquarium fish for tropical freshwater tanks. You can use them as dither fish with aggressive species, like cichlids, and a small group for fish-in cycling.
Danios are great starter fish for beginners, lively and attractive for almost any tank setup. The fish are perfect with most tankmates when in a shoal or school 5 or 6.
Zebra danios only demand a long fish tank with plenty of open spaces since they build up a lot of speed when darting around. Keep more females than males because more males tend to exhaust the female.
As seen, danios are hardy and will tolerate a wide range of water conditions, but they prefer cooler temperatures and high oxygen levels. A few plants, like Java moss, will also be appreciated.
Remember that longfin forms are not as hardy, lively, healthy, or log-lived as natural form danios. They struggle with tankmates and can develop crooked backs.
So, if you are looking for hardy danios for cycling or a newbie tank owner, go for natural forms.
Platies, mollies, guppies, goldfish, white cloud minnows, rasboras, cories, bristlenose plecos, and otocinclus are other hardy fish and ideal alternatives to danios.
Hardy Tropical Freshwater Fish for Beginners
Now…while there are many hardy tropical freshwater fish in the hobby, some, like Angelfish, African cichlids, and Central American cichlids, can be challenging for first-time aquarium owners. Most of these require a large tank and are aggressive.
The best hardy freshwater fish for beginners are livebearers (guppies, mollies, platies, and swordtails), tiny schooling fish (white cloud minnow, rasboras, tetras, endlers, ricefish), and docile bottom fish, like corydoras, bristlenose plecos, otocinclus catfish, and kuhli loach.
Betta and goldfish are also easy to keep and ideal for beginners, but betta fish are fighters and can only live with a small group of schooling fish, peaceful bottom fish, or critters like shrimp and snails.
And…
If you want to start a new goldfish tank, ensure the tank is 40 gallons or more since most can reach 10 inches. You will also need a powerful filter because of their high bioload.
In case you want something a little more challenging but still adorable to keep in your tropical tank (maybe you have a little experience with aquarium fish), you can get a Gourami, Dwarf South American cichlids (Rams, Apistos), kribensis, and even Angelfish if you have enough space.
But if you go in this direction, remember to keep up with your water changes and only add your fish in a fully cycled tank.
That said, …here are a few things you need to know about the fish mentioned above to help you choose the best species for your fish tank!
- Guppies- These tiny colorful fish are ideal for beginners, but they breed a lot, so if you only want a small population, only add male guppies to your aquarium.
If you add female and male guppies together, they will breed even if the conditions in the tank are not the best for them to reproduce.
Another thing to note is guppies in the hobby are inbred and have grown weaker over time, so you may get some that are not hardy enough for beginners and new fish tanks.
Guppies used to be good beginners: colorful and easy to care for and breed, but to get more colors, breeders overbred them, and the result was fish that die if you even look at them funny.
However, many people have gotten guppies and had them for a long time. It all depends on who you get them from.
- Zebra danio-These are very active topwater feeder fish that are hardy and ideal for beginners despite being highly underrated in the hobby. The fish can withstand anything you throw at them.
They prefer cooler aquarium water but can handle a heated tank. Danios are also perfect for fish-in cycling and will accommodate a wide range of tank mates.
You can choose to have zebra danios alone, but they also do well with leopard danios. Celestial pearl and giant danios are hardy, perfect for beginners and new tanks, and an ideal option for zebras.
The only downside with danios is they prefer a long tank because of their activity level.
Zebra danios can also be bullies and nippers, mostly picking on smaller long-tail fish, especially when kept in a tiny tank. Keeping your danios in groups of at least 5 or 6 also helps keep their aggression down.
- Betta- This fish can be the easiest for a beginner if kept solely or with a small group of tiny schooling fish or critters. They thrive in 10-gallon tanks, readily eat pellets and other easy foods, and are incredibly hardy.
They also come in different colors and tail types and have incredible personalities.
Betta splendens are especially ideal for beginners looking for a fish that will live alone in the tank. They do not need to school or tankmates to thrive.
- Corydoras catfish- cories are incredibly hardy and docile fish. They can withstand beginners’ mistakes better than other fish and accommodate most tankmates.
To start a tank with cory catfish, you only need a sand substrate (and everything else necessary to set up an aquarium).
Remember, corys are shy bottom-dwelling catfish that find safety in groups. So, keep at least 6 individuals in your fish tank.
If you do not have enough space, perhaps you are better off with bottom fish, such as Otos or bristlenose plecos.
Please note that corydoras catfish are hardy and ideal for beginners but not ideal candidates for fish-in cycling.
- Molly and Platies-Together with guppies, these livebearers are other species perfect for beginners. However, they reproduce rapidly, so only add males to your fish tank if you do not want them to breed.
Mollies are platies are best if you want a moderately saline fish tank, depending on your water source. Guppies will also accept saline water.
These fish are hardy enough for fish-in cycling, particularly for tropical tanks, which are less ideal for zebra danios.
Start with a group of 4 to 5 platies or mollies.