You may be deciding whether to have a freshwater or a saltwater aquarium. If you opt for the latter, you should know that the characteristics are not the same. A saltwater aquarium requires different care than freshwater. In addition, you will need another type of aquatic plants and fish that are suitable for salt water.
You want to know everything you need to have your saltwater aquarium ready? Keep reading, because this is your post
Saltwater Aquarium Installation
The installation of this type of aquarium requires that each part that composes it be detailed. Therefore, we are going to divide the composition of the aquarium into each important element and describe the needs. Before you start, define the type of project that you want to assemble, because it determines the equipment: a tank only fish (Fish Only) is simpler than a reef aquarium with corals and invertebrates. Reef systems require more demanding lighting, chemical stability, and a slower start.
The fund
The bottom of the marine aquarium must allow enough space for the colonies of aerobic bacteria. These bacteria must share the territory with those anaerobes that will be found within the seabed.
The most suitable material for the seabed is coarse-grained coral sand. This material allows us to have a high content of lime, which helps us stabilize the pH. In addition, it gives us a good decorative and natural style.
Depending on what type de peces you have, you will need one bottom or another. For example, for those fish belonging to the order Perciformes, sandy soil is needed. These species are covered in sand during their nighttime rest. Therefore, it's important to understand its basic needs before purchasing a fish.
If you are going to use a lot of current, consider a somewhat heavier sand to prevent the substrate from blowing away. A thickness of 2–3 cm promotes biological filtration and reduces debris pockets; if you're looking for a deep bed with anaerobic zones, plan maintenance to prevent buildup.
Salt water filtration
To clean the dirt that accumulates in aquariums are needed special filters for salt water. These filters will be able to retain particles larger than those of fresh water. The filters must be cleaned regularly to avoid contamination of the aquarium water at all times. Only with a clean filter, we can make it last longer and keep the water clean.
On the other hand, we should not excessively clean the filter since we will hinder the establishment of bacteria colonies.
In addition to the main filter, the protein skimmer It is key in marine applications: it injects microbubbles that trap dissolved organic compounds (before they become nitrates and phosphates) and extracts them in the form of foam. Reduces biological loadIt improves oxygenation and helps prevent algae blooms. It can be installed in the tank itself (small units) or in the sump.
Aquarium heaters and pumps
Each type of fish requires a specific temperature. For example, if we want to have a saltwater aquarium of tropical species we will need a thermo-heater. This is used to raise the temperature of the water to what the fish need. In this way they will be able to live correctly and not suffer any type of disorder or disease.
Water pumps They are the most important part of the marine aquarium. It is the one that provides the water currents necessary to recreate the marine habitat. Fish require these currents to "feel at home." The pumps must be placed in such a way that there are no places with still water. You have to try to have a uniform current throughout the entire aquarium.
As a reference, in a marine reef aquarium it is advisable to achieve a total circulation of 20–30 times the tank volume per hour using several small pumps to avoid dead zones. For fish-only systems, 10–15 times is usually sufficient. If you have a sump, the return pump must move between 5–10 times the total volume per hour.
Specific lighting for marine
Lighting is decisive If you keep corals. Soft corals and SPS require light with the appropriate spectrum (a mix of white and actinic blue); LPS usually look best with a predominance of blue. Today, quality LED screens They allow you to adjust spectrums and intensities, reducing consumption and heat. Avoid direct sunlight to prevent algae and thermal changes.
In fish-only systems, moderate lighting is sufficient. For reef systems, plan for an 8-12 hour photoperiod and use timers to stable routines.
Sump and return pump
El sum It is an auxiliary aquarium connected to the main one where the equipment (skimmer, heater, biological material, reactors) is housed out of sight. It provides more water volume, improves oxygenation and pH stability, and simplifies maintenance. The return pump ensures continuous flow between the sump and tank; it has an adjustable flow rate of 5–10 times the system volume per hour.
Location, base and lid
Place the aquarium in a place without direct sunlight or heat sources, on a level base with a shock-absorbing mat. A tight-fitting glass lid reduces evaporation, maintains more stable salinity and prevents jumps de pecesConsider the logistics of water changes and potential salt splashing on nearby furniture.
Sea salt
Since using natural seawater is very complicated, you need sea salt. Sea water for the aquarium has to be prepared using reverse osmosis water and sea salt. This makes the conditions within the aquarium more stable and does not produce large variations. SERA sea salt has excellent homogeneity and dissolves quickly and without residue, producing crystal clear sea water.
Recommended process: fill with osmosis water, aerate and heat, add salt little by little until reaching 35 g/L approx., mix 24–48 h and check density with hydrometer or refractometer (1.023–1.026). Do not add salt directly onto fish or invertebrates in the tank.
Live rocks and decoration
The live rocks (or ceramic alternatives) provide surface for nitrifying bacteria and microfauna that help purify the water. Place them in a stable manner (bridges, caves, overhangs) leaving swimming spaces and hiding placesIf you opt for artificial rock, the biological balance takes a little longer to establish, but you minimize pests.
During the first few weeks it is normal to see peaks of nitrites and nitrates. Patience: the system stabilizes gradually. You can use specific quick-setting adhesives or cements to secure structures.
Start-up: cycling and introduction of inhabitants
Once assembled, start the aquarium cyclingThis period allows the conditions to settle. bacteria that transform ammonium/ammonia into nitrites and then into nitrates. With live rock, the process is usually faster. Monitor NH3/NH4, NO2, and NO3 weekly until ammonium and nitrites are at 0.
- 1 phase: Introduce the first detritivores (snails, hermit crabs) when NO2 is undetectable and NO3 is low. They help clean up debris.
- 2 phase: After 2–3 weeks, add additional invertebrates (shrimp, more snails) if parameters remain stable.
- 3 phase: Add soft corals gradually. Hard corals (especially SPS) require more maturity; wait several months.
- 4 phase: Introduce fish last, with the system stable and after the invertebrates.
Apply quarantines whenever possible, and slowly acclimatize each new inhabitant. Avoid overcrowding: in marine habitats, the tolerable biological load is lower than in freshwater habitats.
Control and monitoring of parameters
Maintaining a healthy marine ecosystem depends on a regular monitoring and water changes. As a general guideline:
- Temperature: check daily (24–26 ºC for tropical).
- Density/salinity: 1 time per week.
- pH: 1–2 times per week (7,8–8,4 depending on the system).
- Nitrates and phosphates: 1–2 times per week, especially on reef.
- KH (alkalinity), Ca and Mg: Once a week on the reef; for fish only, check at least every two weeks.
Useful tools: colorimetric tests (fast and cheap), photometers (greater precision), thermometers digital, densitometers or refractometers and, for advanced analysis, ICP (inductively coupled plasma) that detects trace metals and imbalances.
Plan water changes 10% monthly as a starting point (adjust according to load and readings). In aquariums with corals, it may be necessary dose calcium, carbonates (KH) and magnesium, or use complete dosing methods to maintain stable levels.
Plants for saltwater aquariums
The plants that we will place in the saltwater aquarium require some more specific care. Not just any type of natural plant will do. Each type of plant needs a suitable fish tank size. We must calculate the volume of the aquarium necessary to have both plants and fish without being "disturbed".
Here is a small list of some of the best plants for saltwater aquariums.
Shaving brush
These plants have one that resembles a barber's brush. They are green in color and their leaves are feathery. Grows best on sandy bottoms and it does between 3 and 4 inches per year. They are a good idea to combine with fish of the perciform order that need sandy bottoms. These plants require a lot of light and an intermediate water flow.
Bubble algae
These algae are sometimes considered a nuisance since, if the aquarium is not kept well regulated, it invades them. However, if you have good vigilance, they can be one of the best plants for saltwater aquariums.
sea lettuce
It is a green algae that serves as food for some herbivorous and omnivorous fish. They are large, have rounded leaves and a rough texture. They also act as a biological filter since it helps in the elimination of nitrates and phosphates that are harmful. Sea lettuce can be planted at the bottom of the aquarium or left to float freely.
Weed turtle
This plant is also known by the name of maiden hair. It is a green algae with a feathery texture and tube-shaped filaments. Its growth touches 6 inches per year. It can be planted on the seabed and grows in tufts. It releases a toxin that, while non-toxic, is strong enough that it deters fish from eating the plant.
Practical advice: if you incorporate macroalgae in sump or refuge (such as Chaetomorpha), help stabilize nutrients and provide habitat for microfauna, keeping the display free from unwanted proliferation.
Fish for marine aquarium
Like plants, saltwater fish do not require the same care as freshwater fish. Here you have a list of some species of salt water.
Damsels
This species It is highly recommended for newbies to saltwater aquariums. They are 7 cm wide and are solitary. They adapt easily to the environments, so they do not need much care. They are somewhat territorial with other fish, but they do not give problems.
Clownfish
El and clownfish It's a very famous fish due to its name and its colorful body. It's advisable to have a coral bottom for these fish. They are stricter with the temperature of water. They can also be somewhat aggressive towards other species.
Surgeon fish
El surgeon fish It's blue in color and can grow up to 40 cm long. They're very popular, although their care is very complex. If this is your first time keeping a saltwater aquarium, this fish is not recommended. Lives in reefs and requires great lighting and stable temperature.
Angel fish
El Angel fish it is for experienced owners. They can reach 30 cm long and are solitary. They adapt well to aquariums and need large sizes. If they are cared for well, they can last up to 10 years.
A basic saltwater aquarium kit It costs around 80 euros. If you are thinking of setting up your aquarium for the first time, it is better to opt for the starter kits.
Extra equipment and maintenance tips
- Reverse osmosis system: guarantees pure and stable water, reducing algae and contaminants from the tap.
- Automatic filler: compensates evaporation with fresh water and maintains constant salinity.
- Cleaning plan: remove debris from the substrate, keep the skimmer clean, brush pumps, change or rinse mechanics.
- Circulation: Place multiple pumps pointing in different directions and adjust to avoid dead-flow zones.
Recommended water parameters
- Temperature: 24–26 ºC in tropical; in cold marine water, lower and with refrigeration if necessary.
- pH: 7,8–8,4, with good aeration and stable KH.
- Salinity/density: 1.023–1.026 (approximately 35 g/L).
- KH: 8–12 dKH (reef usually prefers 8–9).
- Calcium: 400–450 ppm; Magnesium: 1.300–1.450 ppm.
- Oxygen: above 7 mg/L; good surface agitation.
- Nitrites: 0 mg/L; Nitrates: keep low (ideal <10–20 mg/L depending on the system).
- Phosphates: low levels to avoid algae (especially on reefs).
With this information you can have your marine aquarium ready with the species de peces and most recommended plants. Choose the right type of tank, prepare the water correctly, plan circulation and lighting, and following an introduction and testing schedule will put you in the best position to enjoy a stable, colorful, and long-lasting marine ecosystem at home.