starting a saltwater aquarium for beginners

Starting a Saltwater Aquarium for Beginners. A Comprehensive Guide (with Infographic)

If you are looking for a guide on starting a saltwater aquarium, you have come to the right place.

The expression goes that ‘a dog is for life, not just for Christmas’, but the same can be said for a living, breathing aquarium.
The time and effort that can go into creating the perfect saltwater ecosystem is no small feat, so you’ll want to be sure that this hobby is for you.
After all, you’re looking after a tank full of living organisms, many of which have lifespans in the double-digits.

If you’re sure that you want to delve into the world of becoming an aquarist, then it’s important to follow a certain set of steps, working out what equipment is required, what steps you’ll need to follow to create your new setup at home or in the office, and most importantly, how to spot issues that could affect your new fish.
Saltwater aquariums are different to freshwater varieties, though many of the steps required to get one going are the same, or at least similar.

This article examines all these points in more detail, ensuring that you can get started at this new hobby with minimal difficulty.

Saltwater or Freshwater

It’s a common misconception within the aquarist world that saltwater aquariums are harder to maintain than their freshwater equivalents; however, this is not strictly true.
The truth is that saltwater fish are less resistant to changes in their environment when compared to freshwater fish, and thus not keeping on top of tank changes can have detrimental effects on the health of saltwater fish that would perhaps not be such a problem for tanks filled with freshwater species.

This is due to the relatively unchanging environment that surrounds coral reefs within the ocean.
Fish living in this environment do not experience a large variance in their habitat, in terms of sodium levels, pH levels and so on. In contrast, fish living in freshwater rivers and lakes experience a large variance in their surroundings throughout the year and various seasons.
These traits are so engrained within the DNA of the different fish species that they are present in the fish you’ll keep in your aquarium, too.

In summary, it is not more difficult to set up and look after an aquarium full of saltwater fish, it simply requires better time management and the need to stay on top of tank maintenance.

Laziness around tank maintenance isn’t ideal for freshwater fish,
but it can be deadly for saltwater species.

When starting a saltwater aquarium at home, the rule of thumb is not to rush things. You can’t set up a new aquarium and throw in a large group of fish, then expect them to survive. The tank setup needs to be carefully chosen and put together, and the fish that live within it need to be suited to that environment. Though setting up the tank and equipment you need isn’t always a quick process, that doesn’t mean that it isn’t easy to do. The stages below should help any beginner to get started in this new hobby with minimal difficulty.

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Setting up the Tank

Stage 1

Deciding on where to place your aquarium and ensuring that you have enough space is something that you should do before making any buying decisions.
You don’t want to purchase equipment that won’t fit your housing situation.
Similarly, you don’t want to move around an aquarium once it has been set up and filled.
The location should also not be in direct sunlight, as it can propagate the growth of algae and make water temperature difficult to manage, and it should not be directly in a draft, as this could impact on your ability to closely regulate the temperature of the tank’s water.

Stage 2
Choose an aquarium tank

Once a location has been selected, the next choice should be on what aquarium to buy.
The size of the tank chosen will depend on the size of the fish that you wish to keep and in what quantity, as much as the location that you use.
It’s worth noting that common mistakes made by beginners can quickly run out of control in small aquariums, so it may be better to start with a large tank while learning the ropes.
There are many useful starter kits available on the market, which typically include all of the equipment a budding aquarist needs to get a first-time setup running, so it’s worth shopping around.
Though these kits limit choice around individual components, they often work out cheaper.

Stage 3
Choose a suitable stand

This is worth a mention, as not just any surface or shelf will suffice.
Once filled, the stand will be bearing the weight of many gallons of water, in addition to any coral, rockery or other equipment, and of course, the tank itself.
Additional space will also be required to store the tank’s filter system, and access to plug sockets will be required to power filters, lighting systems, or heaters.
A stand with a solid base to bear the weight of all of the equipment is ideal, whereas shelves – that would place the weight of the load on the screws or brackets holding them – are much less secure.

Preparing your Tank

Stage 4
Ensuring a clean tank

Don’t just assume that an aquarium tank is clean straight out of the box, as it could have been sitting in storage for a long period of time, picking up dust, dirt or bacteria.
The interior of the tank should be rinsed with a new, clean cloth and plain, fresh water. No soap or chemical cleaners should be used, as residue could remain on the glass when it is being filled and potentially harm your fish.

Stage 5
Addition of gravel

Most aquarium hobbyists like to maintain around an inch to two-inches of gravel at the base of the tank.
However, before introducing it to the tank, it’s good practice to rinse your gravel beneath clean running water in order to remove any dust and debris that could contaminate your water.
If you’re planning on adding any particularly large structures as part of the decorative aspect of the tank, then it’s a good idea to do so at this stage, making sure to secure the base of them within the layer of gravel.

Stage 6
Addition of water

When adding water to your saltwater aquarium, you are not expected to retrieve it from natural sources.
Saltwater can be mixed at home, or purchased pre-mixed from stores or online.
However, it should never be created using standard table salt.
Pre-mixed solutions can be expensive, but there are plenty of instructions available online, or often on the back of sea salt mix packages that are bought from specialty aquarist stores.
Tap water should be avoided where possible, but if it is the only option, it should be left for 1 to 3 days to settle, to allow any chemical additives to disperse.
Make sure not to overfill the tank, allowing room for any decorative items or equipment.

Stage 7

Like landscaping, but for your aquarium.

Once your water has settled, it’s time to aquascape, which involves the placement of any decorative items you have chosen for the tank.

Though not a necessity, something called ‘live rock’ can be added to tanks, which acts as a natural filter for the tank.
The process of setting up an aquarium with live rock is slightly different to normal and requires a process called ‘curing’ to remove toxins; however, live rock can also be bought ‘cured’ for immediate insertion into your aquarium during the setup process. Should you choose to use this setup, also known as a FOWLR environment (or Fish Only With Live Rock), then you should research the additional requirements when setting up the aquarium.

Preparing the Ecosystem

You’ve reached the lengthiest stage of setting up a new aquarium and this part is going to require some patience.
This stage is known as ‘Cycling’, and involves a 4 to 6-week period of allowing the tank environment to mature through a process known as the nitrogen cycle.
Though there are shortcuts to this process, which involve throwing some hardy fish into the tank earlier on in the process, they are not considered humane by all aquarists.

Stage 8
Addition of ammonia

Your aquarium requires certain types of ‘good bacteria’ to help convert ammonia to nitrites and then into nitrates, maintaining the homeostasis of the tank.
When ammonia is added to the tank, it is broken down into nitrite and bacteria.
The bacteria break down the nitrites into nitrates.
This can be achieved through the addition of a specialized liquid to the tank, though it can also be achieved through the addition of a couple of resilient fish.
The latter option is less popular with many people, as it is seen as unfair on the fish, who can have a less than pleasant time whilst water levels are unbalanced for this initial period.

Choosing and adding fish

Stage 9
Choosing healthy fish

It goes without saying that the only fish that should be selected for the aquarium is saltwater fish.
Choosing unhealthy fish can also put your other fish at risk, or affect the cleanliness of your water, so only buy from reputable stores and sources.
It’s also important to acclimatize your fish to their new tank by gradually introducing tank water into the bag in which they came, before completely moving them over to the aquarium.
The water that the fish were stored in when purchased should not be poured in.

what equipment you need

The above information covers all the introductory steps for getting your first saltwater aquarium up and running.
What it doesn’t mention in depth is the range of equipment that you will require, including:

This is not an exhaustive list of everything you may need through the lifecycle of your aquarium, but a general guide.
If you plan a reef aquarium, a calcium reactor may also be necessary for the corals.
These components can be picked up separately, though as mentioned earlier, there are many aquarium starter kits that provide most if not all of the equipment required, at a reduced cost when compared to buying all of the components individually.

Identifying Problems with the Aquarium

Now that you’re up and running with a new saltwater aquarium, and once you’ve added your new inhabitants, it’s time to understand what problems to watch out for.
The following five issues are not an exhaustive list of all of the problems that you might face, but they are some of the most commonly seen by new or less experienced aquarists.
Tackled quickly, any issues with the tank needn’t have an impact on the health of your fish.

Water changes

With a good filter in place, this should be an issue that you never really have to experience or manage.
Water can become cloudy or yellow in color when a build-up of fish detritus occurs, comprised of stale food and waste by-products.
Fortunately, the job of your aquarium’s filter is to process these by-products and remove them from the water, so with regular filter cartridge cleans, the water in the tank should not get to this point.
If it does, then the filter likely needs cleaning, or the cartridge changing.
In such cases, a water change would be appropriate.

Temperature changes

Heaters are your best friend when it comes to stabilizing tank temperature, as most can be pre-set to a specific level.
Provided that you avoid locating your tank in areas of direct sunlight or breezes, then it should be easy to keep this factor under control.
There is no one-fits-all temperature, as optimum levels vary from species to species.
To learn more check out our guide on Aquarium Heaters

Development of algae

Algae can develop in a fish tank because of unclean water.
As mentioned above, by-products can develop in tank water, which can act as nutrients to algae.

If algae were to bloom out of control,
then it can eventually lead to stunted fish growth, or even death.

This is mostly the result of two different phenomena; stratification and depletion of oxygen. The latter is simple; increased oxygen consumption by the algae can reduce levels of the gas in the tank water during certain periods of the algae’s life cycle, which can starve the fish of oxygen.
Stratification refers to a process in which the water in a tank can become separated into layers, whereby oxygen-rich water sits at the top and denser, toxin-rich water sits at the bottom of the tank.
This can eventually lead to illness and death among the fish living within the water.
There are luckily way to keep the algae under control.
To help you keep algae under control, you can also stock with fishes that help in eating algae. Check out this article we have on this if you want to learn more on how control algae.

Conflict between fish

When it comes to choosing new fish for the aquarium, you cannot just drop any combination of species into the tank and expect them to get along.

Just like in the wild, there are species that will be compatible, and others that will not.

Research must be conducted to understand where these boundaries lie, otherwise you could end up with an aggression problem between different fish within your saltwater aquarium.
Factors that can help to alleviate such problems include maintaining a tank environment that is not overly crowded, as well as including decorative pieces that have places to hide, such as cavernous rock or artificial habitants.

Natural diseases

Diseases is a natural part of life and fish are not exempt from this problem.
Maintaining a clean tank can help to safeguard against the likelihood of fish contracting marine diseases, as can purchasing any new fish from reputable sources.

If diseases manage to make it into your aquarium, then treatment can be very difficult.

What’s more, marine diseases tend to be highly infectious. Thus, prevention is better than cure.

What Else to Consider

By now, you should know the rough outline of steps required to set up a saltwater aquarium, as well as some of the most common problems that can occur with them.

With all this information, you should be able to
set up an aquarium, cycle the tank and introduce your first fish.

There are some other considerations that are less essential, though it is worth being aware of them.


Coral is an element that you won’t find in a freshwater aquarium – if you do, it’s artificial – but one that can function well as part of a saltwater ecosystem.

Coral is not a decoration that can simply be thrown into a tank and used as a centerpiece.
It is a living organism.

And as it is a living organism it has certain requirements to survive.
There are different types of Coral and can include:

  • Soft Coral

  • Large Polyp Stony Coral (LPS)

  • Small Polyp Stony Coral (SPS)

Check out this article for the details of any type of coral above.
Should you choose to include coral in a saltwater aquarium, then you need to research all of the requirements that they have, in terms of quality of water, water flow rate, lighting, temperature, and water pH levels. This article provide more insights on keeping coral.

Tank size

There are different ways of thinking about tank size.
Beginners often come under the impression that a smaller tank is easier to manage, as there is less space to manage, less to clean, or less fish to look after.
In fact, the opposite is often true; problems that take hold in a smaller tank can quickly spiral out of control compared to a larger tank, where there’s more time to rectify them.

Impact of less expensive equipment

This is a factor that isn’t always considered by new aquarists, but one that should be kept in mind.
Purchasing cheaper equipment can sometimes have a direct effect on the regularity with which maintenance is required on either the equipment itself, or the aquarium, whilst also causing other issues.
Cheaper quality lighting, for example, can have higher power consumption, producing more heat, and thereby increasing water temperature gradually whilst left switched on.
Low quality filters may provide less powerful filtration than more expensive counterparts, or require cartridge changes and cleaning twice as often as pricier models.
In summary, it’s worth considering whether you’re willing to pay more upfront for a better component when first starting out in the hobby.


Setting up a new aquarium for the first time shouldn’t be a difficult task, providing you follow the reams of information available on the correct steps to follow, as mentioned at the top of this guide.
It is not always a quick process, but each step – and the timeframes noted – are essential in ensuring the health and survivability of your fish.
If problems do occur within the aquarium, then it’s essential that they’re taken care of as soon as possible; this is especially important in a saltwater aquarium environment, where problems can spiral out of control much more quickly than in a freshwater tank.

Typically, it’s best to start off with a larger aquarium, as opposed to a smaller tank. This ensures that any issues that do develop are easier to spot, and more time is available to resolve them before they can impact the health of your fish. Size aside, the choice of whether to purchase individual components or an entire starter kit is entirely down to your preference.

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