Best Nano Aquarium

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Nano aquariums are a hot topic, and one of the best ways for those with limited space to get into the hobby. They’re not quite as easy to keep as larger tanks, however, and in this case, it makes sense to start with a good kit to get you going. The question is what makes for a great nano setup?

Let’s dive right in with some great options and additional information to help you ensure you’ve got the best nano aquarium for your home.

nano aquarium


Best Nano Aquariums Overall

These choices are a great place to start, with an excellent overall design and well-thought-out equipment placement.

1. Fluval Flex Aquarium Kit – Best Overall

Fluval is a trusted company within the aquarium community, their canister filters are almost legendary. They also make great inclusive tank kits, including the Fluval Flex line of nano aquariums which feature a vertical bowfront and a rear-facing compartment for equipment.

This is a 15-gallon kit, and there’s also a stand available for those who don’t want to go through the hassle of making their own. The equipment included is pretty basic: a three-stage filter and some moderate lighting but it has a special place for the heater included as well. This makes it effortless to keep the front of the tank uncluttered.

The effect on the glass at the upper edge is a nice touch as well. It helps hide the waterline and any resulting calcium staining that might have happened over the course of the tank’s lifespan.

It’s not perfect. One thing needs to be clear to any prospective buyer: there are only about 10 gallons of “swimmable” space in the front of this tank due to the large filtration compartment. Stock accordingly. It’s also a bit expensive, and the stand that’s available is also up there in price.

On the other hand, it’s hard to beat out the combination of a decent price, excellent equipment, and great build quality with the Fluval Flex. It’s a great kit for those who just want to get started with a fairly unique-looking tank.


  • Great equipment compartment with a good pump
  • Easy to hide equipment in the rear compartment
  • Glass design to minimize the appearance of waterline and hard water stains
  • Adjustable lighting suitable for basic planted tanks


  • Rather expensive
  • Usable space is less than the advertised capacity

2. Imagitarium Freshwater Cube Aquarium Kit – Great for Small Community Tanks

On the less expensive side of things, the Imagitarium Kit is a solid pick. This one is actually part of PetCo’s in-house brand, but it’s a complete kit apart from the the heater. This one utilizes an under-gravel filter, using an air pump to push water through the medium. It’s not the most efficient setup, but it has its place.

The aquarium itself is well-built. The lighting may be a bit of a problem for those looking into growing high end plants but it will work well for most low-to-medium lighting needs. It has nice, rounded corners for even viewing from across the tank as well.

Overall, the equipment is solid if a bit outdated. The moderate cost is great for what you get, but this may not be the right kit for those looking for running an advanced ecosystem. As someone’s first desktop tank it really shines, however.

There are two main complaints. Undergravel filters tend to limit the bioload in a tank, and you’d have to modify the exterior of the tank to increase filtration using a HOB. A mini-canister is your best bet for future upgrades.

Overall, this is a solid choice for a small first tank but it has some limitations. Used for its intended purpose, a small community tank, its great but you’ll want something else for planted or saltwater applications.


  • Great price
  • Easy to setup
  • Decent build quality on the exterior
  • Has most of the equipment you need to get going


  • Undergravel filters are limiting
  • Not the best choice for advanced tanks

3. Tetra Aquarium 20 Gallon Fish Tank Kit – A Solid Start

This is a 20-gallon aquarium kit with most of the basics included. Tetra is a trusted, if somewhat middling, brand in the aquarium world. It’s their equipment included with this tank. Unlike many of the kits we’ll be looking at, this is effectively just a regular 20-gallon aquarium with some included equipment.

This kit includes everything you need except for some substrate. That includes a heater, filter, and thermometer. The filter itself is a Tetra Whisper HOB-style filter sized appropriately for a 20-gallon tank. You can easily replace it or add another filter if you feel it’s not up to par.

While not having a hidden compartment for your equipment can be a pain, you can still hide things well with a bit of experience. It also means that you don’t have to worry about reduced capacity in the swimming area for your fauna.

The downsides? Well, it’s a fairly “normal” tank compared to most on this list. I also consider Tetra’s equipment to be mediocre for the most part, I’ve had quite a few of their HOB filters over the years but only kept them as backups for brands I preferred.

But overall this is a solid tank in the upper range of what’s considered nano. With a bit of lighting improvement, it’s suitable for all tank types and the capacity is exactly what it says on the box with no further need for calculations.


  • Very simple to setup
  • All equipment required for tropical fish is included
  • Easily modified by experienced aquarists
  • The entire tank’s volume can be used by fish and invertebrates


  • Fairly basic overall with no real special features
  • Equipment may need upgrades over time

Best Nano Aquarium Kits for Saltwater

Saltwater tanks are a different ball game than freshwater. They need high lighting, and some also need a bit more specialized equipment. The following tanks are meant for marine use, and have some specialties to make it easier on the end user.

4. Coralife LED BioCube Aquarium Fish Tank Kit – Plug and Play Reef Tank

Coralife makes their BioCubes, which are essentially the Cadillac of pre-built aquarium kits. They have a price to match, but it’s hard to beat a tank that can host a small reef right out of the box. Just be aware that they charge about as much for the specialized stand as they do the tank if you’re looking to keep everything in one brand.

The BioCube hosts a great rear compartment. The best part is that you can see into it, which is a huge bonus if you ever need to troubleshoot the filtration. Reaching around in the dark is not a good time for anyone, and being able to shine a light directly on the problem is nice.

BioCube tanks actually have their own line of accessories for those who aren’t into customizing their equipment. Increased modularity is nice, especially when you can easily pick up things like a UV sterilizer or protein skimmer that remains plug-and-play.

The downside? The cost. The tank is expensive for its size. It’s also a bit hard to access the filter compartment at first, despite being able to see into the rear compartment.

While you’ll pay a premium price, the Coralife BioCube series is able to be used for a reef tank right out of the box. If you don’t mind the price then its the closest to a “plug-and-play reef kit” I’ve ever seen.


  • Works great for reef tanks right out of the box
  • Contains all the necessary equipment
  • Highly programmable lighting
  • Modular with a bunch of accessories available


  • Expensive
  • The filter compartment could have better access

5. GankPike 12 Gallon Saltwater Aquarium Full Bullnose Shape – Decent Budget Choice

Looking at the GankPike series of tanks, you’ll notice they’re a bit cheaper than the majority of tanks billed for saltwater. There are some reasons for that, which we’ll touch on in a bit, but the truth is that it’s still a decent way to get started.

These tanks come with everything you need. You’ll get a heater, filter, and even a protein skimmer out of the bargain. I’m also a big fan of the elongated curve shape, giving you unique view angles. It works well on a bar or other area where you’ll be regularly viewing the tank from both sides.

In addition, the glass is low-iron for a bit better clarity. The included light is actually pretty good, which is nice since the lights are often the weak points in kits. All of this adds together to create a tank that’s suitable for marine use with no serious effort.

The problem mainly seems to be in quality control for the company. A few people have reported getting tanks that were damaged during transit, and the heater is a bit oversized. It’s not likely, but you should consider the fact that some of these tanks need to be returned due to problems with the glass but the rest of the tank is a good start for marine aquarium enthusiasts.

This is a unique little tank with everything you need to get started on a marine aquarium. Just be aware there’s a problem with tanks passing inspection that really should have been reworked. On your end that usually just means a return, but it’s something to be aware of.


  • Comes with everything you need for a basic marine setup
  • Awesome U-shaped design for the glass
  • Decent pricing
  • Low-iron glass for high clarity


  • The included heater is a bit iffy
  • Inspect carefully, some quality control and transportation issues

6. Fluval Sea Evo V Saltwater Fish Tank Aquarium Kit – Customizable and Reef Ready

Once again Fluval makes our list, this time with a dedicated marine tank kit. It’s a bit of an upgrade from the average Fluval tank, with the main emphasis being on including a reef-capable light from the get-go.

Like all of the Fluval tanks, the filtration chamber works great. In this case we’ve got plenty of room for protein skimmers and heaters in the compartments and the separated chambers are actually quite easy to work on.

This tank has everything you need, but the design of the equipment compartment also makes it easy to modify or add more equipment as needed. It’s a nice touch, particularly in the world of reef tanks where sometimes a drastic solution can be required.

The main downside is the location of the compartment. It’s put on one side of the tank, which kind of limits placement options in many cases. The tank’s lights also have a tendency to overheat, which is a death blow for LEDs. While a great light, you may want to make plans for it to burn itself out within the year.

The Fluval Sea Evo V is a great all-in-one kit for those who are still wanting some room for customization. It’s also surprisingly cost-effective considering the brand and the amount of equipment. If you don’t mind replacing the light down the line it’s definitely worth a second look.


  • All equipment included
  • Reef-capable light right out of the box
  • Aluminum, instead of plastic, cover
  • Easy to customize or add capabilities


  • Bad spot for equipment compartment
  • LED light has a short lifespan due to overheating

Best Budget Nano Aquarium Kits

Looking for something a bit cheaper? These kits will get you up and going with minimal fuss or cost, but you may have to work around some of their limitations.

7. Penn-Plax Water-World Radius Desktop Nano Aquarium Kit – Best Budget Nano Kit

While on the cheaper side of things, this rounded glass aquarium is more than up to the task. The tank itself is made of smooth, rounded glass and it comes with minimal equipment to get you up and running. Just be aware you may have to pick up some other stuff along the way.

This tank doesn’t have an equipment compartment, so you’ll need to hide the in-tank filter on your own. I recommend going with a HOB or canister sooner rather than later, but it’s serviceable for small communities with just a heater added to the stock capabilities.

This style of tank is available in a few sizes. I recommend sticking with the ten-gallon, there may be better options if you’re going to go smaller. Oddly enough, despite the mediocre quality of most of the tank’s equipment… the tank itself is nice. It’s probably worth the cost alone.

The downsides are mainly in the mediocre equipment. There’s also the issue of having to move the light every time you want to lift the hood of the tank. These are minor inconveniences, but you should be aware of them.

For a cheap tank, this one actually shines. Stick with the 10-gallon option for the best results and be prepared for switching out equipment eventually, but it’s a great start for a relatively low price.


  • Excellent price
  • Top-quality seamless tank
  • Includes most equipment
  • Great for beginning aquarists


  • Mediocre equipment
  • Build-quality of the hood doesn’t match the rest of the tank

8. Marineland Portrait Glass LED Aquarium Kit – Another Great Budget Nano Aquarium

This 5-gallon tank is one of the cheapest ways I’ve seen to get started with a decent nano aquarium. There are some limitations but like the above tank it actually has a great tank for the price and the rest is basically a bonus.

The tank’s equipment is functional if not my favorite. The filter compartment in the back is a nice touch, and you can switch the LED light between day and night settings so the tank functions as a night light as well.

I’m particularly fond of the portrait style of the tank, which allows you to plant tall plants without incident. Things like Vallisneria sp. always look their best when they’re allowed to grow tall, especially in smaller tanks like this.

Other than the mediocre equipment, the big failing in this tank is that you really only have about 3.5 gallons of swimming room. This effectively means the tank has to be understocked compared to most 5 gallon tanks, there’s just not enough room even if there is a lot of filtration.

This is a great budget tank, but you should be aware it is a budget tank. The equipment is mediocre, but the tank is built well and the back compartment allows a lot of convenience for those concerned with hiding their heaters and other equipment.


  • Rear compartment for equipment
  • Unique portrait-style tank, taller than it is wide
  • Comes with most of what you need
  • Excellent price


  • Effective swimming room is only ~3.5 gallons
  • Included equipment is a bit mediocre

Best Pico Aquariums (≤5 Gallons)

While some of the above aquariums qualify as “pico” tanks, the two below are your best options if you’re intentionally going low in size. Check them out, especially if you’re into smaller desktop tanks.

9. Cobalt Aquatics Microvue3 Aquarium Kit – Incredible Desktop Tank

While small, the Microvue3 is an excellent option for a desktop aquarium. In particular, you’lkl find that the 2.6 gallon model is awesome for keeping Betta or a group of shrimp on your desk but it’s a bit limited in space overall.

The included equipment with this tank is nice. The lights can sustain most green plants (red is always another story) and you don’t lose swimming space to an equipment compartment. It’s perfectly sized for sitting on a desk or countertop without taking up too much room as well.

The light is of particular interest, but the included filter works nicely as well. It’s a small, internal filter with a viewing window for the sponge. Place it somewhere you can see it for the best results, it’s nice to know if a sponge is clogged before you need to open anything up.

The main drawback is the hood. It goes all the way to the back of the tank, which makes canister filters or HOBs hard to use without extensive modification. Any equipment placed inside will also have to be hidden by hardscape elements, which is no small feat in this sort of tiny tank.

If small is the way you’re headed, then check out the Microvue3. It has a great light, good filter, and it’s the perfect self-contained kit for placing on a desk or small table.


  • Included filter is great for an interior filter
  • Light is among the best for tanks this size
  • Excellent, sleek look
  • Designed as a desktop tank with a minimal footprint


  • Very small, you’ll need to stock carefully
  • Hard to customize without losing the hood

10. Fluval SPEC Freshwater Aquarium Kit – Great for Desktop Aqua Gardens

For those who want a planted tank, the Fluval SPEC Freshwater is an awesome choice. It comes with decent filtration, a nice light, and in a couple of sizes. I recommend the five-gallon, the smaller one is a bit harder to use since it has a separate compartment for equipment taking up some room.

The included light is sufficient for most plants, allowing you to create an easy aquatic garden in your home. You may need a higher-powered light for ground covers and red plants, but it will grow the vast majority of flora you bring home from the LFS.

Like all of the Fluval options, the filter compartment is nifty and designed to hide equipment entirely. This allows you to make the most of the remaining space in the aquarium, rather than having to alter your hardscape to hide heaters and filter outlets.

The downsides are pretty small. The tank has about ½ gallon less capacity than it says for the swimming room due to the filtration compartment. It’s also located on one side of the tank, which means that you have an angle where the tank can’t be viewed.

As far as pico tanks go, Fluval SPEC is a great option. It’s mainly a matter of whether you’d rather hide the equipment manually or if you’re okay with having the small compartment.


  • High overall build quality
  • Compartment meant for hiding equipment
  • Light is capable of growing most plants
  • Two sizes available


  • The equipment compartment takes up some swimming room.
  • The compartment is also opaque and located on the side of the tank

What is a Nano Aquarium?

Nano aquariums are just small tanks. The exact cutoff is debatable, but most people agree that it’s either 20 or 30 gallons. I used the latter to evaluate tanks further.

Nano aquariums are great for people who have limited space in their homes. A “normal” 55-gallon tank is four feet long, for instance, and requires a dedicated stand to hold an incredible amount of weight once the tank is filled.

By contrast, nano aquaria start with small desk tanks in the 3-5 gallon range and continue to smaller but not quite tiny tanks like the larger Fluval kit options.

There are some pros and cons to bringing a nano tank home.

The biggest downside is simple: nano aquariums are harder to deal with than larger tanks due to the small water volume. A novice can certainly keep a nano tank (and many unwittingly do) with success, but it takes a little bit more know-how.

Lower water volume means that the tank will fluctuate more rapidly if something is introduced into the water column that changes parameters. In the beginning, this usually just means the volume of waste will quickly become overwhelming if the tank isn’t properly cycled.

Rapid changes in conditions can lead to stress and animal deaths. There’s a certain point where an aquarium reaches a “death spiral” sort of situation, and it will happen more rapidly in smaller tanks.

This can be alleviated by a bit of reading and borderline obsessive use of test kits until you’re more confident.

The biggest advantage is undoubtedly the space saved without a doubt, but nano tanks are often taken up by experienced aquarium keepers just for the challenge. You can fit quite a few different ecosystems into the same place with these tanks.

The bottom line is that nano tanks are great for saving space and fitting more tanks into a small area for variety, but they’re also harder to run. If you’re a complete newbie, I’d start with something bigger but even a complete beginner can run a nano tank with a bit of extra reading and finesse.

If you’re wary about quick water fluctuations, there is a solution while keeping a small tank. You can create a sump that increases the total water in the system to a level you find acceptable with a few pumps and some hoses.

I’ve seen “nano” tanks with more than 70 gallons of water total in the system, but it does require some plumbing know-how to get going. You’ll also still need to find room for the sump, especially if it won’t fit directly under the tank in the stand.

How to Pick a Nano Aquarium

Figuring out which aquarium is right for you will require studying a few different qualities inherent to the aquaria you’re looking at. These range from size to what you intend to keep in the tank.

Let’s take a closer look at the things you need to know when picking out the right kit.


The sizing of your tank is one of the most important factors, especially since nano tanks cover a wide variety of sizes. The biggest differences happen when you drop under five gallons. A system with that little water will fluctuate much more quickly than one which is in the 20-30 gallon range.

If you’re unsure about sizing, go as large as you can fit. Most people can find a place for at least a 20-gallon tank in their home, but 10 gallons are one of the most common tank sizes. You’ll very rarely regret more room in the tank as long as you thought out it’s position in your home first.

Speaking of which, it’s a great idea to measure out and have a space set up for any tank before it reaches the home. Trust me on that one, I’ve suddenly tried to pop another 15-20 gallon tank into my home and then found myself rearranging furniture for a few days to fit it.

The other big factor with the size is weight. Your tank will weigh at least 8 pounds per gallon. That leaves even a modestly sized 20-gallon tank at about 160lbs. That can lead to a bit of disaster if you’re not careful about tank placement.

Included Equipment

The equipment included in a kit ranges from terrible to more than acceptable for the purposes.

The pumps in most of the low-to-mid end tanks are virtually identical. Kits often use a powerhead held behind a sponge filter, with space available for activated carbon or ceramics as necessary.

They’re usually adequate for a normal bioload in the tank, although some arrangements are more prone to problems than others.

The lights are a huge factor if you’re planning on a reef or planted tank. Lights are usually sufficient for low-to-mid lighting plants. Finding lighting suitable for reef tanks and even FOWLR (fish only with live rock) tanks can be more tricky. Outside lighting supplementation should be calculated when you’re picking a tank.

Likewise, if you’re a big fan of red freshwater plants or some ground covers like Glosso. These often require higher lighting than you’ll be able to get out of the box with a nano tank kit.

You should also take note of what’s not included and make sure to pick it up at the same time as the tank. Heaters are one of the most frequent needs for these tanks, most kits don’t include one at all. Still, it’s just a quick matter of calculating which heater you need.

Included Stands

Some kits will come with their own stands, which is a huge bonus if the tank is over the 20-gallon range. While you can generally use standard furniture to hold a 10-gallon tank, bigger tanks get a lot heavier.

They’re doubly useful if you’re planning on expanding the water in the system through the use of sumps or a refugium.

The stands are usually of at least decent quality. There’s too much risk for serious problems when corners get cut on an aquarium stand.

Calculating Costs

Calculating the cost of your new nano aquarium goes a bit beyond just the price of the kit. You’ll need to make sure you account for everything when you budget the tank.

Regardless of the kit that you decide to use, you’ll need the following:

  • Substrate- Whether it’s clown puke for a tiny community tank or high-end, pre-fertilized substrates designed for high-nutrient plants.
  • Heater- Almost no kits come with heaters, you’ll need to buy one separately.
  • Lighting- Lighting is a weak point in both planted and reef tanks, you may need to upgrade lighting immediately for some high light flora or corals.
  • Plumbing- If you plan to create a sump or refugium you’ll need the fittings, pumps, and piping to make it happen.
  • Flora and Fauna- Depending on the style of the tank, it can be easy to underestimate how much it actually costs to get things fully stocked. This is doubly true in smaller reef tanks.

If you’re on a tight budget, it’ll help to map things out before you start making purchases. There’s more to the tank than just the glass after all.

Overall Build Quality

Kits vary quite a bit in quality. A high-end Fluval tank with a vertical bow front is more solid than a low-end 2.5-gallon acrylic tank meant more for a kid’s first Betta than any serious aquarium use.

It can be hard to gauge the build quality of a tank online. The big things to look for are visible plastic components and anything that looks “cheesy” at first glance. Bright plastic, in particular, screams “budget.”

And not in a good way.

Price is a good guideline as well, a tank that’s higher priced at the same size will often be better built. This isn’t always the case, and you kind of run into diminishing returns at the higher end of the spectrum, but it can help.

Take a look at the way the compartments are designed as well, especially if the tank doesn’t feature a canister filter or HOB. Many of these in-built compartments may not be optimal, and anything that’s hidden from view tends to be a step down from the rest.

It’s mostly a matter of analyzing the price and a close inspection of all available information. A well-built tank kit will last for much longer than one that’s mainly built for amusement.

Small Tank, Big Payoff

Nano tanks are small, but they can leave a big splash in your home. Finding the right one is just a matter of finding where the price point, size, and special features all coincide in one spot to make you happy. These small tanks can take quite a bit of work when you’re just getting started, but the payoff is incredible.

I’m of the opinion that the Fluval Flex Series is the perfect place to start looking, it’s a well-balanced system with a few different sizes and great construction.

But the final choice remains with you. So, what are you looking for in a nano tank and how can you get there?