Marine Aquarium

If you are thinking of
setting up a marine aquarium, surely this guide will help you to do it in the best conditions, make as few mistakes as possible and that your marine aquarium works correctly in the long term.

There is a false impression that a marine aquarium is more difficult to maintain than a freshwater aquarium.
This is false,
anyone can have a marine aquarium, even if they have no previous experience.

It also won’t take us long to keep it in good condition, at least not much longer than it would take to maintain a freshwater aquarium.

The important thing here is
the type of habitat that we are going to recreate.There are some really simple and that do not require too many complications, as well as there are easier or more difficult fish to breed in the marine aquarium.

Regarding the choice of fish, it is true that there are marine fish that are easier to maintain, and others that are more delicate, but we also have that problem in a freshwater aquarium.
Certain species of fish are not easy to keep in captivity, while others adapt easily to life in an aquarium.

To start with a marine aquarium, we must take size into account.
A marine aquarium for beginners should have at least 200 liters, it is an aquarium sizewhich allows us to minimize any possible beginner mistakes… I know you might like to start with a nano marine aquarium , but I don’t think it’s the best option.

From that minimum size, we can buy the aquarium that we like, always taking into account the type of fish that we are going to raise and their quantity.

Aquarium location

The marine aquarium should be placed in a place in the house where it receives little or no direct light.

The reason is obvious,
avoid the proliferation of algae.


If our aquarium is going to have more than 300 liters, we must check that the chosen place can support it without problems, as well as the table where we are going to place it.

As a precaution and to absorb any type of irregularity in the surface where we place it, or unevenness in the floor, it
is advisable to place an expanded polystyrene sheet under the aquarium or some of the materials that are sold on the market for this purpose.


Once placed in its final location, we must clean the aquarium well. We must not forget that all kinds of chemical products have been used in its manufacture, and that in handling it we will have filled it with traces.

For its cleaning
we will avoid chemical products, only a sponge, clear water and suitable products for aquariums. Failing that, we can use bleach diluted in 5% water.

Aquarium water

Once the aquarium is clean and dry, we can start filling it with water.

the water that we will use will be filtered by a reverse osmosis system , but if this is not possible, tap water can also be fine, as long as it does not contain nitrates, phosphates, chlorines, or silicic acid.

Most likely, your tap water has chlorine in it.
Chlorine evaporates, so we
could use tap water by letting it sit for 24 hours.

Water temperature

The temperature of the water must move above 25ºC, avoiding that it drops below 20ºC and does not rise above 29ºC.

Although we are not going to introduce fish into the aquarium for a few days, it is advisable that the water takes the right temperature.

To regulate and maintain the temperature of the aquarium
we must use a thermo-heater . There are several types of heater on the market, although the most popular are submersible.

Water density

To this water, we must add sea ​​salt for aquariums , that is, we first put the water and then the salt, never the other way around.

The water has to reach an approximate density of 1,025 gr / cm3, which we will modify depending on the needs of the marine fish that we are going to introduce.

Density must be measured with hot water, since
water becomes less dense when it is hotter, and vice versa.

Water quality. Aquarium filters

To maintain optimal water quality, filters must be fitted . These filters can be installed inside the aquarium or also outside.

Internal filters usually come with the
marine aquarium kits , because they are somewhat cheaper.
External filters are usually the ideal ones for a good size aquarium, due to their greater filtering capacity. Although to be honest, nowadays the filtering capacity of both filters has improved a lot.

As a rule of thumb to choose the correct aquarium filter, depending on the size of our aquarium, it
should be able to filter three times the amount of liters of the aquarium. Thus, a complete 100-liter marine aquarium will need a filter of about 450 liters per hour.

The important thing when we choose an aquarium filter is that it adapts correctly to the size of the aquarium, and that they offer us
mechanical, biological and chemical filtering of the water.


The Skimmer are not essential in a marine aquarium, but we could say that they are «desirable».

They are in charge of reproducing the natural process of beating the waves in the sea, which
is why they are also called skimmers.

When the sea churns the water through the waves, what it does is introduce air into the water.
The air traps decomposing elements, such as proteins and lipids, generating that foam that we see on the crest of the waves and on the shore of the beach.

What Skimmers do is «help» to
keep the water in the marine aquarium clean. They collect the water, beat it by introducing air, the air collects nitrates and other waste, eliminates this waste and returns the clean water to the aquarium. 

Substrate and decoration of marine aquarium

The decoration of the marine aquarium can contain various materials: corals, flint, calcareous rocks, lava blocks, and of course substrate , which can be coral sand and calcareous sand.
Prohibited materials in the decoration of a marine aquarium: wood and metal objects.

aquascaping advises that before proceeding to mount an aquarium, we must make us some sketches, list the necessary materials and prepare before starting to assemble the aquarium.

A good idea is to
assemble the aquarium design before introducing the water , to see how it looks.


Lighting is another point to take into account within the marine aquarium, since excessive lighting will make algae proliferate and poor lighting will result in the health of the fish and all the living elements of the aquarium.

In the market there are many types of aquarium lights, even the aquarium that we buy can come with its own installation.

Some of the
types of aquarium lamps that can be included are:

  • Metallic vapor lamps. In this case, it is convenient to use D lamps, which simulate natural light and avoid NDL lamps, neutral white.
  • Fluorescent tubes. Fluorescent lamps offer a high light output, so it is preferable to use T5 fluorescent lamps, which have a diameter of 16mm.
  • In a marine aquarium, at least two fluorescent lamps should be installed, if three are installed, a blue one can be added.
  • LED lighting. LED technology offers correct lighting at low cost. To know the ideal parameters, consult your usual store.

How long does it take to get fish into a marine aquarium?

The marine aquarium needs a period of adaptation, until the water conditions are correct to reproduce the marine life.
This process usually lasts about three months, in which we will have to progressively adapt the aquarium, and only when we verify that everything is correct, we can introduce fish and / or invertebrates.

Commissioning of the marine aquarium

Before introducing any type of fish, it is convenient to gradually adapt the aquarium and the water to the optimal conditions.
For a week we must leave the aquarium running, with all its elements, substrate, decoration, etc., running with its filter and the water heater, but without any type of lighting.
After two weeks, we will gradually turn on the aquarium lighting .

The first day we will maintain the light for one hour, the second two and so on progressively until we reach ten hours of illumination per day.

After the first week that the aquarium is without lighting,
live reef rock can be added progressively.

Measuring water quality

During these three months of preparation and tuning of the aquarium water, it will go through different phases, until the conditions are right.
In a first phase we will be able to observe the growth of green algae with a filamentous appearance, the substrate can be seen covered with diatoms and later it is possible that higher algae appear.

It may give the impression that the water is in good condition, but it is a mistake.
It is not yet prepared to withstand the contamination produced by food and fish excrement, and if we introduce a specimen, it is possible that it will die within a few days.

During this adaptation process,
we must check the water quality at all times, to correct any problems, if necessary.

Once the three months recommended for the aquarium water to be in optimal conditions (and there is no proliferation of algae), we will proceed to
gradually introduce the different inhabitants of the aquarium.


The feeding of the fish is very important, both for the fish themselves, and to maintain the quality of the water.
They should be fed every day, but only the amount that they are going to eat, to prevent debris from depositing at the bottom of the aquarium.

In addition to seawater fish, invertebrates can be introduced.

marine invertebrates feed on trace elements, which can be added to the aquarium water , as recommended by the manufacturers.

Although it is not complicated to set up a seawater aquarium, it is advisable to follow the previous advice, so that the process is pleasant and we do not have any type of problem.

Fish for marine aquarium

These are some of the species that you can introduce in your marine aquarium , and of which I have spoken in the blog:

Tips for caring for saltwater fish

  • It controls that the salt level is kept within optimal parameters, between 1,020 and 1,023 mg / l.
  • Before mixing different species, find out their compatibility . In each of the tiles, you have their character and with which other fish can share space.
  • Each inhabitant of the aquarium needs his living space. It is important not to put too many specimens within a small space, which seems sufficient to us, it may not be so for each of the species, each one needs an aquarium size and a certain amount of water.
  • Make sure all the fish eat. There are species that are very slow and are not good at fighting for food, while others are too fast and voracious.
  • Keep an eye on the lighting . This has to be correct, we are reproducing a natural habitat: the hours and intensity have to resemble the biotope to reproduce.
  • Temperature is very important to maintain life in the aquarium. Saltwater fish come mostly from tropical areas, the temperature must be between 15ºC and 27ºC.
  • Observe the quality of the water, carry out frequent checks, carry out regular water changes and keep the interior of the aquarium clean.

Publicaciones relacionadas

Deja una respuesta

Tu dirección de correo electrónico no será publicada. Los campos obligatorios están marcados con *

Botón volver arriba