Most hobbyists and fish keeping experts will recommend starting out with a larger tank typically anywhere from a 40 - 75 gallon for a first timer. This is because a larger tank will have more water volume for added stability. However, not everyone can afford a tank this size (or have the space for one) so a nano reef tank is a legitimate consideration for those with small budgets. While a nano reef tank is still expensive compared to a freshwater tank, one does not need to shell out thousands of dollars on a small setup. With proper preparation and care, one can successfully keep a smaller nano reef aquarium and often times produce a stunning aquarium that rivals the looks of larger aquariums - at only a faction of the cost!
So what exactly is a nano reef tank? Well, let's define it here as many hobbyists will break out the nano reefs into two categories:
Nano Reef Tank - Reef aquarium that is 40 gallons or less
Pico Reef Tank - 5 gallons or less
We are going to discuss nano reef tanks in this post only. Pico reef tanks are the subject of an advanced aquarist nature and definitely not for the faint of heart. So now that the term nano reef tank has been defined, let's talk about why they are cheaper. Let's break it down into several reasons:
Lighting is cheap in a nano
Nanos are far easy to break down and move
The first part are the setups. A Nano reef tank will usually have a bare bones type of setup. There is usually not a sump involved which means there is no plumbing to deal with. A simple powerhead is used for flow and flow tends to be less complicated because a nano reef tank will often be coral type dominant vs. mixed. Protein skimmers are not necessary in the tank, though many hobbyists will use them. When a skimmer is used a hang-on back protein skimmer is typically used. Due to the small size of the tank often times a hobbyist will opt for purchasing distilled or RODI water from a local fish store instead of investing in a RODI system. Your electrical bill will also be cheaper as well since you will not be using that much equipment.
Lighting is another cost savings. One of the most expensive pieces of equipment for larger tanks are the lighting systems required for higher intensity corals and the number of lights needed for longer tanks. With a nano reef tank, the lighting cost is cost down drastically. Some nano reef tank kits will actually come with lighting and this lighting is plenty for soft corals or fish only with live rock setups. Even for a high end lighting system, you will likely not spend more than $200 on lighting for a nano reef tank (and in most cases much less than this).
Mobility is another great benefit of a nano reef. These aquariums often are placed in tight areas like a desktop, bedroom, or on a stand in a living room. Because they are able to be moved easily, one can move them throughout the home to suit the home decor changes you make over time. They are also one of the aquariums that you can safely place upstairs. With larger systems, one has to consider the structural support of the home to ensure it can support the weight upstairs. If your home does not have the proper weight support for a large system, it is likely that you would need to increase the support or consider a different location. There is also water spills to consider with a larger tank upstairs.
I will open and honest and say that a nano reef tank is more suited for an experienced aquarist. There are three reasons for this:
The main reason why there is lack of stability is due to having less water volume in the tank. Evaporation in particular, is extremely brutal to a nano reef tank. Every other day freshwater top-off is usually needed to keep salinity parameters in check. Sometimes, the task is a bit overbearing so you will often see an auto-top off system (ATO) installed in a nano reef tank.
Temperature is another concern, especially if you live in a warmer climate. Temperatures can swing during the summertime especially if you live in a home without air conditioning. When in doubt, a cooler room is easier to deal with than a warmer room in the home. You should also utilize an open tank setup. Your lighting system must be suspended above the aquarium either with a suspension kit or the suspension mounts your LED system comes with. A canopy is a no-no for a nano reef tank.
Nutrient stability is the last issue with a nano reef tank. Because you do not have a larger volume of water, weekly water changes are a must for a nano reef. In a larger system, it is reasonable to perform bi-monthly or monthly water changes. There are even cases where other hobbyists go months after establishing a complete nitrogen cycle in the tank. This unfortunately is not a reality in a nano reef tank. You will not have enough volume and space to establish a complete system and with the stability issues - it is a best practice to continue weekly water changes even after running the desk successfully for some time. The good thing; however, is that water changes are a breeze in a nano reef tank because you changing a very small amount of water volume.
Because of the inherent stability issues with a nano reef tank, it is not uncommon to spend extra time monitoring the tank. Leaving your tank unattended for more than two days can be disastrous if something would happen like a heater failure. It is best to know a friend in the hobby if you are planning to be out of town to watch your tank. You can use my earlier blog post of a list of hobby clubs near you to find other hobbyists in your area.
Due to the limited amount of space and stability issues of a nano reef, your options for fish are very limited. When thinking about fish to put into a nano reef tank, we need to consider the following:
When thinking about the fish's natural temperament, we really want to focus on getting a fish that has a mellow temperament. This is likely going to be the only fish or one of the only fish in the tank so if you are considering placing more than one fish in the tank, we really want to purchase a peaceful fish. If you are happy with only one fish in the tank, we can do that as well, but we have to keep in mind any invertebrates that you want to add - especially shrimp. Some fish like damselfish are known for attacking shrimp when space is lacking. It may be best to consider avoiding any damselfish if you are considering shrimp.
Your fish's size is the next consideration. We really want to purchase a fish that is going to get no larger than 3 inches for a nano reef tank. This means no large fish like Tangs. I do know some hobbyist placing a tang in larger nano reef tanks like a 40 gallon tank in the short term, but if you are new to nano reefs or do no have the money for a future upgrade I would not consider a Tang for the sake of the fish's livelihood.
The hardiness of your fish is another important factor. A nano reef tank will have parameters fluctuate no matter how much try to prevent it. Because of that, you want to make sure you have the most resilient fish you can buy. Look for tank bred fish or fish labeled as easy to keep or hardy.
Reef safe fish is our last consideration. It actually many not be a factor if you are considering a fish only with live rock setup, but nevertheless you do not want to house a known coral picker in your tank. Your space is small and you will not have many corals. If you have a coral picker, it will not take very long for your fish to wreck havoc on a small tank. This means that even borderline reef safe fish like dwarf angels are out of the consideration for a reef tank. It's best to take the risk with a larger tank with fish like that as you can remove the picker before things get our of hand.
So now that I have outlined the important factors, let's talk about fish that fit this criteria. Several fish from my top 10 best saltwater fish for any reef tank post make great nano reef tank fish. You can check out that post for further info, but here are several fish that would fit well in virtually any nano reef tank setup:
Keep in mind when it comes to stocking fish in a nano reef tank, we want to lightly stock our tank. You are dealing with a small amount of volume, limited space which will increase aggressiveness, and limited bioload capacity from having a smaller tank. I know that movement and personality of the fish is the big draw with aquariums, so this takes me to the next section of our article.
As we covered earlier, one of the issues that nano reef tanks face is their lack of size. The very thing that makes them an attractive option for small spaces also puts them at a disadvantage when it comes to stability. Chemistry and temperature changes happen quickly in a nano reef tank. Because of this some corals are going to be ill suited for a nano reef tank. We talked about fish earlier. So what are some good choices when it comes to corals?
Because we know that our fish choice and stocking is limited, we really should focus on corals. Picking a variety of the correct corals will add lots of color and movement to a nano reef tank that will mitigate the lack of space and stocking options. I will break down the consideration factors below:
Hardiness is our number one factor when it comes to selecting corals in our nano reef tank. We want corals that can take a few parameter swings. This makes soft corals the prime candidate for nano reef tanks.
The movement of corals will create a flow in the tank and make the aquarium pop. Without the movement, you are going to have very little moving life in the tank because you will likely have one or two fish in the tank. Lots of movement sometimes comes with added aggressiveness.
Because of our lack of space, aggressiveness is a bigger consideration than in larger tanks. Spacing aggressive corals too close to each may cause coral deaths, especially with corals with strong stingers like some LPS corals. The preference would be to house corals that are known for living in dense spaces.
Variety is our last consideration. We want to have a variety of colors available in our corals because we will not have many fish. The good thing is with the availability of aqua cultured and fragged corals, the variety of colors are ever increasing with this hobby.
So now that I have gone through the selection factors for corals in a nano reef tank, let's talk about setups. I'm going to focus on coral type tanks as those are the easiest ones to explain. I will go through the following:
The Bullet Proof Setup
A bullet proof setup in a nano reef tank would comprise of easy to care such as soft corals, polyps, zoas, and mushrooms. These types of corals are great choices for a nano reef tank as they are tolerant of a few fluctuations in chemistry and temperature in the tank. Not only are these corals hardy, but they will also provide much needed motion in the tank. Here are a few examples of corals that would make good additions in a bullet proof setup:
Finger Leather Corals - Kenya Trees & Sinularia
Mushroom Corals - Actinodiscus, Ricordea, and Rhodactis
Polyps & Zoanthids (Zoas)- Mix and Match Freely just be careful of polyp and zoa domination in a tank
Finger leather corals are fast growing and great for fulling vertical space while mushrooms, polyps, and zoas can fill the mid and low spaces. Their rapid growth will cause them to fill out a nano reef within a few months. The main advantage with corals like these is they have a weaker stinging ability compared to other corals. This means that they are able to be in close proximity to each other without too much stress. There is always some type of territory combat in a reef aquarium, but soft corals are less likely to kill each other off and you are given more leeway for to make up for mistakes.
The other great thing about a bullet proof setup is your lighting requirements are pretty simple. Virtually any type of LED fixture available for a nano reef tank is going to provide ample lighting for these corals and the lighting solution will be easy on the wallet. I have not even mentioned the color variety available - especially for zoas. I have seen many beautiful Zoa only nano reef tanks that are absolutely stunning. It is very easy to get addicted to Zoa collecting and building up your own mini water garden.
The LPS Setup
While not as hardy as a soft coral setup, and LPS setup can provide one of the most stunning looking aquariums. With many LPS corals to chose from, they provide a variety of colors and motion in the tank.
The main issue with LPS is there aggressive nature. Careful spacing will need to be provided especially when it comes to Hammer, Frogspawns and Torch corals. These corals are know to kill off other neighboring corals if placed to close to each other. Here are a few examples of corals that would make good additions in a LPS setup:
Because of the more aggressive nature of Frogspawns, Hammer, and Torch corals, it would be best to only have a select few of these. In smaller nanos, it is probably best to avoid these corals because of their aggressive nature and their size. Candy Canes, Acans, and Micro corals however are more peaceful. You lighting is going to need to be more intense than with the bullet proof setup, but any reef grade LED should work for an LPS setup.
The SPS Setup
Small Polyps Stony Corals or SPS corals are a very popular reef tank setups in the hobby. If you have been to any of the big reefing forums, you will see that many of the feature tanks on those forums are dominated by SPS setups. They are the hardest of the three setups I have outlined. Here are the reasons why SPS are usually not a good idea for a nano reef tank:
So while they are not a good fit for a nano reef tank, many hobbyist will still place SPS in corals in the tank. I am not going to get into harder to keep SPS corals as that is the subject of a more advanced coral keeping post for another time. I want to concentrate on the hardiest SPS corals out in the market that would be appropriate if one desires to keep SPS corals in their nano reef tank. When looking for SPS corals in a nano reef tank, we want to find SPS corals that are hardy and are tolerant of subdued lighting conditions. Here is the list of the best SPS corals for a nano reef tank:
What I am doing here with these recommendations is I am replicating the big draws of an SPS setup (branching and plating corals), but selecting SPS corals that are on the hardier and less light intensive end. Both bird's nest and pocillopora will gave you that branching look of an Acropora coral while the chalice coral will give you a look similiar to a Montipora coral.
While they are on the hardier end of the SPS care spectrum, it is all relative. This type of setup is far from a bullet proof setup. SPS corals are still an advanced level coral and you would still need to keep a watchful eye on water parameters.
Any experienced hobbyist will tell you that patience is the key when it comes to reef aquariums. It is pronounced even more in a nano reef tank. In a larger system, sometimes you can get away with rushing things because you have the buffer of a larger volume of water. That is not the case in a nano reef tank. Take the time to cycle your tank correctly, ask a ton of questions, and do not impulse buy. Any mistake or impulse purchase gone bad will get ugly very quick in a nano reef tank.
I hope that this article helped provide clarity in any questions you had about keeping a nano reef tank. The nano tanks are amazing when running well and are more favorable than larger systems. With careful planning and some good maintenance habits, you can enjoy a nano reef tank of your own. If you are interested in purchasing a nano reef tank, we have a collection of nano reef aquariums that we sell in our store and you can always contact us with any questions you may have. We are happy to help you along the journey. Thanks for reading and see you next time!