How Many Neon Tetras [Recommended] In A 20-Gallon Tank?

Neon Tetra is one fish that comes at the top of every fishkeeper’s list.

There are 2 primary reasons behind this –

1. Neon Tetra’s appearance makes them appalling to newbie fishkeepers;
2. Neon tetras have low care needs, making it easy to care for newbies.

With these two major points, if you agree to keep neon tetras in 20 gallon tank (a recommended stepping stone), there may come other questions bombarded in your head –

1. How Many Neon Tetras in a 20 Gallon Tank?
2. Compared to a 20 gallon high tank, how many neon tetras should I add in 20 gallon long tank?
3. How many neon tetras should I keep in a 20 Gallon Community Tank?
4. Or how many suitable tank mates should I keep with neon tetras?

How Many Neon Tetras in a 20-Gallon Tank?

I’m starting off by addressing the 1st question – how many tetras in a 20 gallon fish tank?

I’ve asked around a couple of experienced fishkeepers (who’ve managed over 20 neon tetras in a 20-gallon tank), and their recommendations were pretty close to each other.

Newbie fishkeepers are bound to make silly mistakes. So, you should keep 10-15 neon tetras in a 20 gallon fish tank.

Disregarding these recommended safe numbers may further lead to unwarranted issues with your tank’s filtration system, causing nitrate poisoning and raising the pH level to abnormally high.

However, if you genuinely have a relatively smaller or bigger fish tank, these are some of my recommendations –

Should You Follow the Infamous 1-Inch Rule?

I’ve heard many fishkeepers recommend following the infamous 1-inch rule in stocking neon tetras or related smaller fish!

Before I share my opinion, let’s recap how this 1-inch rule works –

What is the 1-inch rule in fishkeeping? I’ll explain this in layman’s terms – A fish measuring 10 inches in length would be fine in a tank holding only 10 gallons of water. A 55-gallon aquarium could also house two 27-inch fish and vice versa.

This means that if you’ve got a 20 gallon tank, you should keep 20 neon tetras in it.

Honestly speaking, the 1-inch rule is helpful in certain conditions.

But you should not solely rely on this rule as you should consider factors such as decors, plants, substrate, and tank filters when making a stocking-related decision.

How Many Neon Tetras in a 20 Gallon Tank with Betta?

I don’t know why newbies prefer keeping bettas in an even smaller fish tank.

As an expert in fishkeeping, I’ll always recommend you to keep betta fish in at least a 5 gallon fish tank.

Now suppose you’ve got a 20 gallon fish tank, leave the 5 gallons for betta’s, and for the remaining space, you can have at least two schools of neon tetras.

So this means, One betta and about eight neon tetras can easily share a 20-gallon aquarium.

But to be honest, Neon Tetra and Betta Fish are not the greatest fish for a 20-gallon aquarium. 

But to be honest, Neon Tetra and Betta Fish are not the greatest fish for a 20-gallon aquarium.  This is because bettas are highly possessive and hostile fish. They need a lot of room to move about in.

And this lack of space may turn ugly after your neon tetras bite at a betta’s long, attractive fins in retaliation for the betta’s hostility.

Although you can avoid all this by keeping them together in a bigger tank where both neon tetras and bettas have sufficient room to move and “mark” their territory.

How many guppies and neon tetras in a 20 gallon tank?

After bettas, Guppy fish is another preferred choice for newbie fish keepers.

So, in this section, you’ll learn how many guppies are allowed with neon tetra in a 20 gallon tank.

Before I share the numbers, let’s do some basic maths.

On average, male guppies can grow up to 1 inch, whereas female guppies grow twice their size.

So, suppose you’ve allocated 1/2 of your 20 gallon fish tank to guppies.

Then how many guppies should you keep with a school of tetras fish?

If you want to give the guppies and neon tetras proper space, you should never exceed their limit to more than 5.

In short, for a 20 gallon fish tank, I recommend you to keep 5 guppies with 6 neon tetras.

How many neon tetras in a Community Tank?

Until now, everything in this post revolved around a neon tetra fish tank.

What if you’ve got a big community tank?

How many neon tetras should you keep in it?

I believe that’s where the 1-inch or even the 2-inch rule can come to your rescue, as you’ll have to allocate several neon tetras to available space.

Related Post:

7 Peaceful Community Fish For Your Home Aquarium

How many neon tetras in a 20 gallon long tank vs 20 gallon high tank?

When keeping neon tetras or any other nano fish, the only thing that matters the most is space.

Even with a limited space of 20 gallon tank, you can stock at least 30 neon teras!

How’s that possible when I recommended 15-20 neon tetras earlier?

That’s because it was for a 20 gallon high tank, whereas if you want to keep 20-30 neon tetras, you should keep them in a long 20 gallon tank.

OK!

But what’s the difference between them?

An increase in the water’s surface will result in a higher rate of oxygen transfer, which is crucial to the well-being of your neon tetras. Tanks of heights and widths hold the same volume of water, thus, while the high tank is more visually appealing, a taller tank comes with more surface area. 

Parting Thoughts

If you’re just starting your fishkeeping journey with a 20 gallon fish tank, it’s better to pick a smart approach.

And a smarter approach would be to pick a wider tank.

This way, you would be able to add more fish and give them more space to swim.

But be careful!

When you increase the number of neon tetra in your 20 gallon fish tank, they’ll require high maintenance from your end.

If you’re not up for the challenge, it’s better to stick with 15 neon tetras in your tank.