Simple Rimless Nano Reef Tank - Beginner's Guide 2023

Nano Reef Tank

Nano Reef Tank Popularity:

Small desktop reef tanks under 20 gallons are becoming more and more popular. Today’s equipment makes it far easier to keep a stable nano reef tank. Small saltwater aquariums look great in any room and having one on your desk will allow to you unwind while you are working. Livestock selection must be done carefully to avoid overstocking or aggression. A nano reef tank generally will require more frequent attention than a larger system as the smaller water volume will be less stable in all aspects such as salinity, temperature, ammonia and nitrite. Big parameter swings in a little tank can cause a real problem so it is best to keep on top of maintenance and water changes. Frequent water changes are a must for smaller reef tanks especially if you are not running a protein skimmer. The great thing about nano tanks is that although they require frequent water changes, they are normally easy to do and much quicker when compared to a large system.


Freshwater To Saltwater:

I wanted to take a minute to talk about the conversion from freshwater to saltwater and go over few key aspects to consider. Any tank can theoretically be a beginner saltwater tank, nano tanks do not need protein skimmers (although this will benefit the water quality) and you can use a normal aquarium heater. The four main differences are the water, the livestock, the aquascape and the filtration. The tank water must be premixed reef salt with RODI water to a salinity of 1.025 (measured with a refractometer) and of course the tank must be cycled. You can install a RODI unit and order reef salt to make water at home, another option is to buy all your saltwater and RODI you need from your local aquarium shop. You will need a supply of RODI water on hand to top up evaporation. When setting up your aquascape you must use aragonite sand, normal freshwater river sand contains a lot of silica and can contain other unwanted contaminants you do not want in your reef tank. In terms of filtration, the saltwater side of the hobby differs from freshwater, the main bulk of the biological filtration will be done within your live rock rather than inside the filter. You will need lot of flow in and around your live rock to get optimal conditions for beneficial bacteria growth, a wavemaker may also be needed to increase flow. When cycling a saltwater tank, it is best to use a source of ammonia and a source of beneficial bacteria to help the cycle along the way. Cycle your tank before adding any coral or livestock. Keep in mind most reefers will not consider a tank fully mature until a year after setup, saltwater tanks are generally more long term than a typical planted freshwater tank. Once cycled you can choose your livestock, it’s worth putting in some time to research your options. There are some colourful interesting nano livestock options out there such as cleaner shrimp, clownfish and hermit crabs to name a few! The experience of keeping a saltwater setup will provide you with lots of benefits throughout the fishkeeping hobby. Understanding more about the uptake of elements, lighting and flow is useful for both freshwater and saltwater.


Basic Rimless Reef Tank Concept:

A rimless nano reef poses a few challenges when compared to a standard larger reef tank with a sump. One option is to drill and plumb your new rimless tank so you can have a sump and keep all your equipment in there. However, while this can be done it is not an easy process for someone with no experience. Most beginners want a small simple saltwater tank on their desk which may be their first go at the saltwater side of the hobby. Generally, I would say to go with the largest tank you can as it will be far easier to keep water parameters stable. Something around 15 -20 gallons is a good place to start if you have never kept a reef tank before. You will need a heater and some form of filtration on your nano reef. One option is to use one or two powerheads to create flow throughout the tank and live rock, this simple method of filtration is technically all you need. Although, if you ever want to remove debris from your water or add some extra media an internal or hang on the back filter can work well as it will give you the flow you need and the option to add some media if you ever need it. In terms of filter media avoid the usual sponge found in freshwater setups this will only harbour nitrates, fine filter floss can be used but it must be changed very regularly. Once your equipment is in place, it’s time to aquascape! Get some live rock and aragonite sand. Create an interesting rock structure, try to think about how you are going to maintain the tank moving forward, leave a good amount of open sand bed. Think about what your want your nano saltwater tank to look like before purchasing any lighting. You do not need any specific lighting if you are going to setup a live rock and fish only tank. If you plan to keep corals, I advise you purchase a reef tank led, which will produce the correct temperature of light for your future corals. If this is your first nano reef tank, I would say your best bet is to keep hardy soft corals such as mushrooms, pulsing xenia, leather corals and toadstools. These corals do not have high light requirements and will tolerate some swings in water parameters. Recently there has been an explosion in popularity of macro algae saltwater tanks. Macro algae are the plants of the saltwater world! A normal freshwater planted light can work well in a macro algae tank with lots of green shallow water macroalgae species. Some macro algae keepers also dose planted tank fertilisers to make sure the macro algae has all the nutrients it needs.


Please note: Some soft corals such as Palythoa and Zoanthids contain palytoxin which can be dangerous if correct saftey precautions are not taken. Please research you coral species thoroughly before purchasing them and always wear protective gear when required.


My Nano Reef Tank Experience And Advice:

I want to start off by offering the two biggest factors for success with a nano reef tank: keep it simple and do your research. I have a lot of knowledge about this side of the hobby, but I have only ever kept small reef tanks with soft coral or LPS. Clownfish are my all-time favourite fish, so my saltwater setups are usually catered towards a pair of them. I have been keeping small reef tanks for over 8 years. My most successful and longest running nano reef tank is still up and running smoothly as I type this. My nano reef has been running successfully for over 2 years now and I keep it simple, which I think is the key to my success. I have a 60cm rimless tank with a DIY clear plastic lid to stop jumpers and reduce evaporation. I only need three plug sockets for my equipment on this tank, I have a heater, a small but powerful internal filter and a reef tank LED. The internal filter turns over the water a little more than 10 times an hour, which is on the low side for most reef tanks. 99% of the time there is no media at all inside my filter, I rely on the live rock for filtration, I do sometimes put fine floss in the filter for a few hours after a maintenance to collect debris. This is a low flow and low light reef tank; I only keep hardy soft corals which has worked well for me so far. I keep xenia, sinularia, toadstools and a neon green cabbage coral (my pride and joy). Most of the coral has grown well over the last few years, particularly the neon green cabbage coral which has grown ten times its original size. Because this is a relatively small tank, I only have a pair of clownfish, a hermit crab and a turbo snail. I have only run into one problem so far with this tank, algae. Over a year into the setup, I came back from holiday to find some hair algae growing on the live rock. I didn’t think much of it at the time but after a few months it had gotten out of hand and was starting to look ugly. I realised as the fish were growing, I had slowly been feeding more food which caused my nitrates and phosphates to increase. I have managed to almost eradicate the algae completely by doing more water changes and manually removing as much of the algae as I can. Always act when you notice a problem, beating algae in a reef tank is not a quick process. I am sure there are some experienced reefers out there who are completely underwhelmed by the description of my simple nano reef tank and that is completely fine! As you progress in the saltwater hobby most people become drawn to more difficult species of coral and more complex systems. I will take the plunge someday soon but owning and maintaining multiple tanks means that this simple nano reef tank is the perfect fit for me right now. Think about how much time and resources you can reasonably put into your nano reef and plan from there. My simple setup has been a joy to maintain and watch over the last few years and I plan to keep it running for many more!



AQUAnatur was created by an established UK aquarium installation and maintenance company near London which has been running for over 25 years! Our team are very experienced and happy to help offer advice with any aquarium questions. We are always available via phone or email Monday-Friday, feel free to contact us, we would love to help! AQUAnatur supply a range of aquariums and aquascaping products. If you have a question, please leave a comment or contact us via phone or email.

By Alasdair McPhail

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