Nano Reef Tank For Beginners (Tips)

Treetopz, CC BY-SA 4.0, via Wikimedia Commons
Treetopz, CC BY-SA 4.0, via Wikimedia Commons

Nano Reef Tank For Beginners (Tips)


I get it, saltwater aquariums can be bulky and hard to find the space for, and on top of that, they can be expensive! But did you know that there is another way you can have a saltwater reef aquarium in your home?

Nano reef tanks might be just the thing to make the hobby work for you. The care and knowledge needed for a nano reef tank might be a little bit more than the average tank, but it could also be that much more rewarding. It just takes a little bit of patience to get everything correct. 

Reef aquariums can be breathtaking but in the form of a nano tank, they are affordable, too. It all comes down to whether you take the time to learn about the different species best suited for a nano tank and specific requirements for each one. The key to success is research.

Essential Reef Tank Maintenance Tools


Water changes are essential to reef tank health. This siphon makes it easy.

Fish Net

A good fish net is a must. Removing dead fish quickly ensures overall tank health.


Heater settings can be inaccurate. A good analog thermometer is a smart backup.

Test Kit

Maintaining proper saltwater parameters is essential to fish and coral health.

What is a Nano Reef Aquarium?

A Nano Reef Aquarium is a saltwater aquarium that is as much as 30 gallons and as small as 5 gallons. This makes the aquarium much more compact and easier to afford the option for aquarists on a strict budget. If you have limited available space in your home, a nano reef tank might be just the thing for you. Nano tanks are designed to be easy to move and find locations for. In terms of possibilities, these aquariums hold a lot of possibilities.

However, they do require that you are familiar with the needed parameters your tank should be at for the organisms living inside.

Are Nano Reef Tanks Hard to Care for?

Nano Reef tanks are not necessarily for new aquarists. You might think, “oh what can the harm be it is a smaller tank it should be easier?” Here is the thing, A nano reef tank requires you to be much more tuned in to the water parameters and ensuring the required nutrients are available to your marine life. I think it would be best if we took this one step at a time. You may be familiar with a traditional tank but some of the normal practices are a little different with nano tanks.

First, let’s look at why the water parameters can be a little trickier with a smaller aquarium. Since there is less water in the smaller nano tanks, you have to worry about the impact of evaporation much more than if you had a larger tank size. The evaporation from the tank can throw off the salinity and temperature of the tank. You will either need to make it a part of your routine to manually top off the lost water or you can find an ATO (auto top off) system to control this detail.

Though you might have the ATO, it does not substitute for proper water changes. In a larger tank that is properly set up, you might get away with changes that are weeks apart. That is not a possibility with a smaller aquarium. You must be willing to perform full water changes at least once a week. There is some good news though! You will only have to change 30 or fewer gallons of water with a smaller aquarium.

Temperature changes can occur presence of evaporation. You need to be mindful of the changes or else you might have a few disgruntled fish. You can mitigate the change in temperature by being consistent with your water top offs or by purchasing an AOT system.

The biggest requirement of a nano tank aquarists is being a little more detail-oriented. The requirements of the tank and the lack of stability over a few days will require that you take the time to adequately monitor water parameters and perform the weekly changes. It is not that much harder if you are aware of the responsibilities. The challenge of a smaller aquarium is the time you need to take to research the equipment, species, and care so that you are making a healthy and safe marine life community.

What do I Need to Start a Nano Reef Tank?

You have read through the warnings and the benefits of a smaller aquarium and you have decided that it is the path forward for you but what do you need to set one up? Here is a quick list of things that you should consider when planning your nano reef tank.


  • 5-30 gallon aquarium
  • Wavemaker
  • Thermometer
  • Refractometer
  • Live Rock
  • Quality Reef Lighting
  • Live Sand (or bare bottom)
  • Heater
  • Filter

Consider Carefully

You will want to consider the materials needed with care for your saltwater aquarium. Not everything is completely needed depending on the type of nano reef tank you are trying to cultivate. Check out more posts at Reef Tank Resource for more information about the supplies involved with aquariums!

You want to take extra care when deciding what reef lighting you might want for your tank. The lighting required for something like a bulletproof setup will be different than if you were trying to go for an LPS setup. The coral and fish species that you choose to host in your saltwater aquarium will make all the difference when it comes to what specific equipment models you need for your reef aquarium.

Setting up a Nano Reef Tank

You have read through the warnings and the benefits of a smaller aquarium and you have decided that it is the path forward for you but how do you set one up?   

Remember to Cycle Your Tank

This should be the first step in setting up your nano reef tank. You begin this process before you place any fish in the aquarium because you want to avoid introducing fish to an environment that is not prepared safely for them. You want to set up your live rock in your nano reef tank because the bacteria from the rock will be what helps in the nitrogen cycle. If you need help with aquascaping, check out this article for more tips!

After you install at least half of the live rock you will be using the actual process can begin. Test ammonia after 3 days and keep checking every few days after that along with nitrite levels. Since a nano reef tank is much smaller than the average saltwater reef tank, cycling will not necessarily take the typically prescribed 4-6 weeks. When nitrite levels measure zero you can start to test for other for nitrate. Tanks are cycled when ammonia and nitrite levels are at zero and nitrates are being produced! Once cycling is over you can finally begin to add your fish and coral. There are manual tests available for all of these parameters but you can also buy a monitoring system if it is within your budget. A monitoring system can cut down on the time it takes for you to care for your tank but you should still have a manual test on hand at all times. Technology is never full proof and if I learned anything over the years, the manual tests are always useful when in doubt.

You also do not need much light during this process. Try to only use light for a few hours every day while your tank is cycling for the first time.  

What Kind of Marine Life can Live in a Nano Tank?

Nano Tanks are great for coral and small since the tank has limited space. The coral will help to supplement some color to your tank and provide what few fish you might have with a nice backdrop. You will want to plan out what organisms will be taking up residency in your tank as early as possible, A good plan will make all the difference because of how interconnected the behavior, temperaments, and needs of the marine life can be.

What Kind of Fish is Best for a Nano Reef Tank?

As you might expect, nano tanks area little limited in terms of the fish that can live happily in them. The smaller tank requires that you are being more careful about the amount and the kinds of marine life you are buying for your tank.

You will want to avoid adding too many fish to your tank and it probably shouldn’t have to be said but your fish should be on the smaller size for a nano reef tank. The fish you want to introduce to your fish tank should probably not grow to larger than 3 inches in length. Like I said earlier, a nano tank’s parameters will fluctuate much more than a traditional aquarium tank. The fish you introduce to the tank then should be able to live through these changes.

You also should keep in mind that your fish and other marine life are all species that will get along. For instance, you might have a fish that will want to pick at coral. The issue here is that you will not have space for a lot of coral. The little coral you do have will be killed by the coral picking fish.

Here are some reef fish suggestions that might make a great addition to your nano reef tank. These are only a small fraction of the fish you could consider. I have also written some personality traits you might need to be wary of for these particular fish but make sure to research the species further if you hope to introduce them to your nano reef tank.

  • Ocellaris Clownfish
    Can be a great addition but must be mindful they don’t overbreed.
  • Hancock’s Blenny      
  • Helfrichi Firefish
    Don’t keep more than one. This species is not a fan of their own species.
  • Firefish Goby
    These little guys are known to jump. Careful with those lids.
  • Captive Bred Pajama Cardinalfish
    Does not do great with aggressive fish.


I am speaking from a general perspective. If your budget is higher than the average person and you have experience with other tanks and marine species, you might be able to stretch some of the guidelines a little. However, I want to stress that you should only do that with proper experience and research.

What Coral can go in a Nano Reef Tank?

Corals can be finicky creatures and in a nano reef tank, the coral will need to be hardy to endure the instability of the tank. The better the coral can deal with changes in temperature and salinity the better suited as a nano reef tank candidate it can be considered.

Balance is the biggest thing when it comes to nano tanks. Everything is interconnected and something as little as the movement of corals can create issues down the line. The coral movements can be mesmerizing and enjoyable. One of the biggest benefits of the coral is the added complexity they bring to the tank. The movement can cause corals to hurt one another and we trying to avoid that.

Here are a few setups as to how best to structure your coral within your nano reef tank. Remember for all of these that the requirements for the coral are all different. For example, the lighting for a soft coral in a bulletproof setup is not the same as the lighting requirements needed for a hard coral in an SPS setup.

The Bulletproof Setup

This setup focuses on soft corals, polyps, mushrooms, and zoas. A soft coral doesn’t have a hard structure. These corals are hardy and will withstand the changes within the reef aqua. This is your best if you are just a beginner. The corals in this setup are more forgiving than some of the other methods to come. If you are new to caring for corals, this setup will help to get your feet wet. Plus, unlike the next few setups, I will talk about, the bulletproof setup works with practically any LED lighting fixture. The light requirement for this setup is very lenient so, you won’t have to break the bank for these lights.

Bulletproof Corals for Beginners

    • Colt Coral
    • Green Star Polyps
    • Leather Corals
    • Mushroom Corals

The SPS Nano Reef Setup

This setup consists of small polyps and stony corals or SPS for short. This setup is not for beginners. It should only be done if you have experience with nano tanks and the corals used in this setup. The SPS setup is more difficult due to the specific. The light and temperature need to be carefully monitored for the success of this tank setup. The corals used are very sensitive to the changes in the tank parameters. You need to have more intense lighting for the SPS setup They look really nice though if you can successfully meet their requirements. You also need to pay attention to the water flow for this type of setup. The coral used will require a stronger direct water flow to help them thrive.

SPS Corals for Beginners

    • Birdsnest Coral
    • Montipora Caps
    • Stylophoras (Stylos)
    • Green Bali Slimer

The LPS Setup

These corals are large polyp stony coral (or LPS). This setup has a lot of diversity in its colors and look. The corals used though can be a little combative and hurt neighboring coral. In this setup, you will want to be mindful of where you are placing coral species like Frogspawn and Hammer corals.  You will need to invest in better lighting than the bulletproof setup of corals but this only requires a low or medium indirect water flow.

LPS Corals for Beginners

    • Frogspawn
    • Hammer Coral
    • Tonge Coral
    • Blasto Coral

Additional Nano Reef Tank Tips

Now you know what can go in your new nano reef tank aquarium but what other best practices might you benefit from knowing? Because as we all know, there is more to tending an aquarium than throwing a few fish, rocks, and coral into a tub of water and calling it a day. The devil is always in the details so let’s review a few.

  • Always try to keep the light of your saltwater tank dimmer and bluer if you have the lighting fixture for it. The light will benefit the entire tank community and helps with the overabundance of algae.
  • Don’t add too much to the tank! Each marine creature you add to the tank is another picky guest that has its own needs and wants to thrive. The more you pack in the more guests you need to accommodate and eventually, the small space just won’t enough space for the tank’s inhabitants.
  • Evaporation. I know I have mentioned this multiple times already, but I think it is important to get across. The evaporation experienced by a nano reef tank can have big effects on the population of your saltwater tank. You want to make sure you are checking your water quality and topping off the water when appropriate, as well as changing water when the time comes.

Keeping your Nano Reef Tank Clean

Nano tanks thanks to their small size can quickly change water levels depending on how well you maintain them. Keep in mind the following methods at hand for when you need to clean your fish tank.

  • Algae Magnet
    The algae magnet is one of the best tools for cleaning the glass of your tank. The tool allows you to clean your tank without getting your hands wet. Plus, you can more easily reach some of those hard to reach spaces on the glass. You do want to be careful with cleaning near the sand. The sand could get stuck between the magnet and the blades of the cleaner and then you risk scratching your glass. You might want to invest in a hand scrapper that can reach down to the sand to prevent the sand from getting stuck and scratching your glass.
  • Turkey Baster or Coral Feeder
    Something as simple as a turkey baster will help to keep your nano fish tank in top form. By stirring up the sand, you disrupt the algae and waste that is stuck in the sand. If you do this before a water change you are helping to remove more waste with your water change than if you had skipped directly to the water change.
  • Trimming Scissors
    There is a good chance that your healthy aquarium will have a growing plant system. Due to the smaller space and depending on the plants you are caring for, it may be necessary to trim your plants more often.

Do I need a Protein Skimmer for a Nano Reef Tank?

A protein skimmer will create a foam that collects waste, so essentially skimmers help to keep your tank cleaner for longer by automatically collecting some of the waste that naturally builds up.

You do not necessarily need a protein skimmer for your reef aquarium. It really depends on what you are keeping in your tank and how big the tank is. Water changes make all the difference for a smaller aquarium. If you are keeping up with water changes, you can probably get away with not skimmer without any real issues. Skimmers can be expensive, and you don’t want to waste money in your budget for one if you are going to do work that will deem it unnecessary. You will want to change the water 10 to 20 percent weekly to help compensate for the lack of skimmer.

Conclusion: Take your Time

All in all, the most important takeaway from this article is that you need to take your time. Even if you are an experienced fish tank aquarist, you will benefit greatly from taking the time to understand what the diminished space means for your water parameters and the marine life that you choose to keep in your aquarium.

The small space requires that you are taking your time to research and find the best species for the type of tank you are setting up. Every plant, coral, and fish you add to your tank could have a ripple effect on the other fish in the tank. You want to ensure that no fish’s care will cause the care of another fish or coral to be neglected.

Reef aquariums can be beautiful, and a smaller aquarium can make that view more of a possibility on a budget. Nano reef tanks can be a lot of fun and are great for their small size, but you need to carefully construct their ecosystem to ensure lasting success.

Did you find this article helpful? Help Us & Share it.
Recent Posts