In this article, you’ll learn why you might want to use Hardy Fish for your new aquarium as well as the type of hardy fish for different setups, whether it’s a small 10-gallon nano tank or a small outdoor pond.

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Let’s get into it.

Hardy Fish For New Aquariums & The Nitrogen Cycle

When setting up a new aquarium one of the things most beginners will overlook is how important the nitrogen cycle is.

Without getting into the details of the nitrogen cycle and whether or not you should use fish or go fishless, just know that the nitrogen cycle is what makes your water safe for your fish and if you skip this step or at least aren’t aware of it, you’re likely to harm or even kill your fish.

As a note, in my opinion, the best and most hardy fish to use for cycling your tank would be a goldfish.

For two reasons;

First, most fish use their gills to rid their bodies of ammonia. Because of this, the ammonia levels of your fish will be the same as the water, which is most fishkeepers recommend you keep the ammonia levels as low as you can.

Second, Goldfish, on the other hand, can remove ammonia through their waste which usually means the goldfish will have less ammonia in their bodies than the water column.

It’s because of this ability that you will often see Goldfish surviving in horrible water conditions, they can simply handle it.

Watch this video from Aquarium Co-Op Cory does a great job explaining what the nitrogen cycle is all about.

That said, there are some fish that many fish keepers will use during the nitrogen cycle to help establish your tank.

Here are some good hardy fish for cycling your new tank;

  1. Goldfish (Non-Fancy)
  2. White Cloud Minnows
  3. Danio
  4. Feeder Guppies

Hardy Fish For Beginners

Another reason you may want to consider using hardy fish in your aquarium is that you’re a beginner and new to fish keeping.

Like most things in life you’re likely to make a mistake here and there, it’s no different with fish keeping.

If you start with a fish that has very specific requirements or is very sensitive to swings in temperature, water parameters or other factors you could end up killing your new best friend.

So having a few hardy fish in your tank that can live through some of the problems you may encounter when starting out will help ensure you don’t kill any fish as well as keep you from getting frustrated and abandoning this great hobby.

If your tank has cycled here are a few great hardy fish for beginners;

  1. Most Tetras
  2. Betta Fish
  3. Platies
  4. Sword Tails
  5. Bristlenose Plecos

Options For Each Tank Size

It’s not only the type of fish that you need to consider when starting in the hobby. While many of the fish listed above are very hardy – they all need a certain amount of room.

For example; the White Cloud Minnow might be great for a 10-15 gallon tank but I wouldn’t use it in a 5-gallon tank or smaller.

With that said here are some hardy fish ideas based on some common tank sizes.

For 5 Gallon Tanks

Overall a 5-gallon tank is very small so you’re limited to what you can put in it.

But here are just a few ideas you can use.

  1. Cherry Shrimp
  2. Betta Fish
  3. Nerite Snails

For more ideas check out our guide on Stocking a 5-gallon tank.

For 10 Gallon Tanks

Here are a few of the hardy fish for a 10-Gallon Fish Tank:

  1. Neon Tetras
  2. Cardinal Tetras
  3. Kuhli Loach
  4. Cherry Barb
  5. White Cloud Minnow

For 20 Gallon Tanks

If you want the perfect tank for a beginner you should start with a 20-gallon tank. It has just enough water volume to ensure you don’t mess up the water parameters too much and it’s just the right size to manage for a beginner.

That said, it also allows you to keep a few larger fish which could make for a very cool set up.

Here are a few hardy fish for your new 20-gallon tank;

  1. Platy.
  2. Swordtail.
  3. Molly Fish.
  4. Cory Catfish.
  5. Dwarf Gourami.

For Planted Tanks

Planted tanks are awesome, I just recently set up my first one!

You can check out my post on how I set up my first 10-gallon planted tank, I go over all the equipment as well as the fish and plants I used and include some videos.

The thing with planted tanks is that if done right they can help stabilize the water parameters in your tank a great deal which means if you’re a beginner, you might be able to use some fish that aren’t considered hardy.

If you’re looking to set up a planted tank here are a few semi-hardy fish you could use.

  1. Ram Cichlids
  2. Gourami
  3. Rainbow Fish
  4. Killifish
  5. Swordtail

For Small Outdoor Ponds

If you’re considering setting up an outdoor pond just be aware there are a few considerations that are unique to ponds.

For instance, animals like birds, cats, and depending on where you live, insects and reptiles that may look at your pond like it’s a buffet.

Also, most outdoor ponds are not heated so you’ll not only want hardy fish but you’ll want to use cold water fish species that can handle the temperature swings from late night to mid-afternoon.

If you think you’re ready to take things to the next level? Check out this article about hardy fish that you can use in a small backyard pond.

Some of the fish listed are;

  1. Koi
  2. Golden Tenches
  3. The Classic Goldfish

Which Hardy Fish Are Right For You?

At the end of the day, you need to be honest with yourself and decide where you are at in your fish keeping journey.

If you have a little experience and want to set up a planted tank or a small outdoor pond, you may want to try a few fish that might be a little more delicate than the fish noted above.

But if you’re just starting out I’d recommend you stick with one of the hardy fish listed above but always ensure the tank you use is the right size.

If you need some ideas for a community tank then check out our Tank Mates and compatibility guides.

What Does Hardy Fish Mean?

Hardy fish are easy to maintain and easily able to adapt to most water parameters such as during the nitrogen cycle.

Are Platies Hardy Fish?

Platies are one of the most popular fish species and are very easy to keep and considered to be very hardy. They are compatible with most other peaceful fish species and breed very easily.

Are Neon Tetras Hardy?

These tetras would not be recommended during the cycling phase of your aquarium, however, once your aquarium is established Neon Tetras are a very hardy fish.