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Marine tank set up

Here is a comprehensive step-by-step guide on the marine tank set up process that explains everything you need to know to grow a healthy marine ecosystem at home.

Keeping a marine aquarium at home can be a rewarding and enjoyable hobby for adults and children alike.However, it will take a little bit of knowledge and patience to grow a breathtaking marine aquarium.

A healthy and well-maintained fish tank has therapeutic effects and can reduce stress levels. It can add fascinating colors and a variety of organisms within your living space.

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Top 3 Mistakes Newbies Make Setting Up Their Fish Tank.

55 Gallon Reef Tank55 Gallon Reef Tank

Decide On The Type Of Marine Tank Set Up

When you decide to set up a new fish tank, the first step is deciding what type of marine system you want. In this regard, there are three types of marine aquariums; reef tank set up, fish only tanks and fish only with live rock. 

  • Fish Only Tank - Fish only systems with fish, but may also have algae, snails and detritus eating crustaceans. In this system, you don't introduce live corals or other sessile (non-moving) invertebrates. Many decorative fish-only tanks have decorative rocks, artificial seashells, and plants or synthetic coral. They are the cheapest to set up and maintain. You do not need fancy lighting rigs and other coral sustaining equipment like protein skimmers.
  • Fish-only With the live rock - FOWLR fish tanks are fish-only systems where you add live rock harvested from real reefs. You can also introduce a few invertebrates. FOWLR systems make your aquarium appear more natural since marine plants, algae, and other organisms will live within and encrust the live rock.

  •  Reef Tank Set Up - Reef tank systems are the most prestigious and challenging marine fish tanks to set up. The focus of these systems is on the corals and not the fish. They usually include one or two token fish. 

For reef tank systems, you use soft corals, large polyp stony coral, reef-building corals, anemones and other marine invertebrates to grow a real-life coral reef in your home.

You may introduce a few reef-friendly fish species to add interest and movement, control algae without disturbing the corals. It is the most advanced and visually stunning aquarium that you can have.

You need a fair amount of experience and knowledge in water quality testing to manage a reef tank set up. As such, as a beginner - it is advisable to start out with a fish-only or FOWLR aquarium. You can upgrade later after you have mastered these two marine fish tank systems. 

Choose The Aquarium Material, Size, And Location.

There are two material choices for marine aquariums; glass and acrylic. Glass fish tanks are the recommended choice for beginners.

They are more expensive, resistant to scratching and maintain clarity over time. On the downside, they are heavier than acrylic and can be prone to leakage and breakage under the required conditions.

However, if you opt for a good brand with quality glass builds; leakage and breakage should not be a problem.

Acrylic aquariums are much lighter than glass, and can be made into various shapes. However, they scratch easily, cost more than glass and require more maintenance. Acrylic aquariums tend to become foggy from minor scratches and change color over time.

There are factors that you should consider when determining the size of the fish tank to get. First of all, you have to figure out where you will place your fish tank and the amount of space that you have. Bear in mind that you should place your marine fish tank away from:

  • Natural light ( heats up the water and causes algae blooms.)

  • Windows (they result in either heat or cooling of the water, so it’s a terrible location for temperature stabilization.)

  •  Heater and /or radiator.

  • Air conditioner vents.

  •  Excessive noise.

  •  Vibration (to keep fish stress levels to a minimum.)

It is best to use your marine fish tank as a focal point in the room you will place it. The stand or support you will use to hold your fish tank should be capable of supporting the weight of the filled fish tank. Go for a solid stand rather than an open frame one. 

Solid stands will offer more support and will allow you to store equipment and supplies out of sight. This will be important if you are going to utilize an external filtration unit that has to be placed underneath the stand.

You must ensure that you will place the tank correctly the first time. Trust me, moving a fish tank full of water and marine life is a hassle. 

However, the main factor that will determine the size you choose is the types of marine fish you want to keep in it and the number you hope to keep in the future.

Certain marine fish species like Angels and Tangs need a minimum area to live and swim to stay healthy. Your budget will play a role as well. Larger tanks carry a heftier price tag (easier to maintain though).

Nonetheless, always go for the largest marine fish tank that you can afford. A larger tank will give you more stocking options later. In addition, bigger volumes of water mean bigger buffering capacities of the water. This means that it will take much longer for shifts in water parameters (such as PH drops) that could result in fish loss. This is especially helpful if you are a beginner in learning the ropes. 

Choose The Marine Aquarium Lighting

Marine LED LightingMarine LED Lighting

It is extremely important to provide the right kind of light for your marine tank set up. Having a regular light cycle every day is vital for the well-being of all the fish in your tank. You should set-up lights with timers to ensure a consistent day and night cycle. The recommended amount is 8-10 hours each day full of light. 

Ensuring a cycle that is regular helps reduce stress thus minimizing the chances of disease. Lighting will be even more essential in case you have a plan of keeping live rock / coral in your own tank. Most corals utilize light to produce energy, and many of the species will be due to lack of proper lighting. There are three main options when it comes to marine fish tank lighting:

  • Fluorescent Light - Offer one of the most convenient ways to light your fish tank. They are cost-friendly and come in a wide range of colors and sizes. They are also energy efficient. There are fluorescent light fixtures that you can mount directly to your fish tank if you want to go for an open top tank. You can also mount other types of fixtures inside a canopy. This type of lighting is great for fish-only systems. You should replace this fluorescent lighting every 12 to 18 months.

  • Metal Halide Lighting – Refers to high-intensity systems of lighting, which are more popular with the more experienced aquarium hobbyists. They provide more light almost similar to that of natural day-light. It is the preferable option if you plan to introduce a lot of coral (hard coral) in your marine fish tank set up. 

    This lighting penetrates deeper into the water than fluorescent or LED lights, making it ideal for huge/deep fish tanks. However, this type of lighting is very costly to install and consumes a lot of electricity. In addition, they can increase the water temperature if you keep them in a canopy as they burn hot.

Next you have to consider filtration, now that you have selected the fish tank and the lighting system. There are a number of filtration methods available. Generally, the best methods are those that utilize biological filtration, so that beneficial bacteria eliminate toxins that come from the water. 

Fish produces ammonia as a toxin. Bacteria convert this ammonia into nitrite; which is a slightly less toxic compound. The second bacteria type converts nitrite into nitrate; which is a much less toxic compound. Monthly water changes will remove the nitrate as it builds up. This is referred to as the aquarium nitrogen cycle. 

Your first step is deciding whether to use a sump. This is a small tank, which seats beneath your fish tank. It offers a convenient place for maintenance and addition of extra filtration like a nitrate reactor or protein skimmer. It also helps to keep the water oxygenated. 

The downside of keeping a bottom sump is that it requires proper plumbing. As a beginner, you can manage without a sump if it requires a bit of experience. If you choose to set up without a sump, below are some filtration methods you can opt for:

  • Under-gravel Filter - This device consists of a disc, which pulls the water down through a substrate and then recirculates it back into your tank. The most commonly used substrate is gravel. It provides a medium for the growth of nitrifying bacteria. This filter is often powered by an air pump or even air stone.

It is an ideal filtration system for smaller fish tanks. This filter works well with a fish-only tank, but you have to maintain the cleanliness of the gravel. It's not a suitable option for a tank that holds more fish than its filtration capability is much limited. The use of under gravel filters requires a cycling period before you can add fish to the tank. 

  • Wet or Dry Trickle Filter - This type of filter is attached to the end of the tank. It works by pumping more water out of the fish tank inside a container with a water filter media. The media provides a place for nitrifying bacteria growth. 

This filtration system is ideal for fish-only systems. It is worth noting that Wet / Dry trickle filters require a lot of maintenance work to keep the system clean and unclogged. It also requires a break-in (cycling) period before you can add fish to your aquarium.

  • Canister Filter - A canister filter is a container situated below your fish tank. This system typically has a pump that is built-in, which draws more water outside the tank, through the filter and then pumps it back up. It employs a combination of biological and mechanical filtration.

This system is a better choice when compared to a trickle or under gravel filters. It can be used successfully in a large marine fish tank and does not require the cycling period before you introduce fish. However, they need regular repair and can as well be a hassle to disassemble and clean.

  • Live Rock or Live Sand Filtration - This is the most preferred marine aquarium filtration method by far. Live rock is rock, which has been cultured in the ocean and has some filtering bacteria. The live sand is sand cultured in the ocean and contains filtering bacteria. 

Live rock and sand serve as platforms for the growth of the bacteria that provide filtration. These filtration systems also offer a natural setting for fish and coral. It is preferable to use both live rock and live sand in your marine fish tank. You can obtain both from your local fish tank retailer from an online store.

An added benefit of these systems is that you will not require a length cycle time because the filtering bacteria is present within the systems. The live rock and live sand systems are commonly used with a sump below the tank.

Now that you have the marine fish tank prerequisites (aquarium, lighting, and filtration) figured out, you can proceed with the setup and assembly.

Below we are going to guide you systematically on how to go about this. There are some water parameters that you will need to monitor to grow your marine fish tank. 

These parameters include salt content, water temperature, PH value, ammonia/nitrite/nitrate levels and carbonate hardness (for reef tank set up). The tools needed to measure these parameters can be easily purchased from an online store.

Ensure that you carefully read all the instructions on their use.

  •  Basic Cleaning

Using a soft, clean, steam washcloth, wipe out the interior of your fish tank, the outside, and the top rim thoroughly. Rinse out the fish tank with lukewarm water and allow it to air dry. Remember to use soaps, detergents, or any form or abrasive cleaners on your tank.

  •  Install the Fish Tank Equipment

Set up each piece of equipment necessary including the filter or protein skimmer, heater and thermometer, a circulation pump and aquarium lights. Ensure that you carefully read the instructions that come with the equipment.

Fortunately, numerous pieces of equipment are designed to operate with various tank sizes as we mentioned before. 

You have a lot of options available to suit your needs and preferences. Always ensure that each equipment you have specified is built for marine / saltwater aquariums.

Your local aquarium retailer , or online store will have all the necessary equipment. They will also advise you on any queries you have so far free to ask about anything that you are unsure of.

  •  Add the Substrate

This is the material that you place at the bottom of your marine fish tank. For marine aquariums, the ideal substrate is sand or even the crushed coral unless you go for the under-gravel filter. In which case, you will obviously choose gravel. 

A suitable substrate for a marine fish tank is the one rich in calcium. Go for crushed coral or aragonite (fine sand). The substrate should form a layer about 2 to 4 inches thick at the bottom of the tank. 

Rinse out the substrate in a colander before adding it to your tank. Use 1 pound of substrate for each gallon of water in your fish tank. Ensure that you spread it out over the bottom of your tank evenly. You can also choose to go bottomless’ and use no substrate at all. It all boils down to personal preference. However, the substrate is ideal if you plan on introducing fish that burrow.

  • Prepare and Add Aquarium Water

Tap water is not recommended for a marine fish tank. City water supplies contain chemicals that can be harmful to fish and invertebrates. The suitable type of water to utilize is Reverse Osmosis De-Ionized water. This water is available at an aquarium retailer or even some grocery stores. Alternatively, you can invest in an RO/DI filter unit. 

The next step is adding sea salt mix to the RO water. The sea salt mix from the fish tank store will have instructions for the right proportions. Your hydrometer (a testing device that measures dissolved salt levels) reading should be 1.025. You should never use table salt in your marine fish tank. 

There is also the option of buying ready-mixed salt water. Ensure that you check for leaks as you slowly add the prepared water to the tank. Fill your fish tank about a third of the way up to leave room for your own decorations.

  • Run your Filtration System for 24 hours

Turn on your fish tank’s filtration system and allow it to run for about 24 hours before adding any live rock or organisms. This is to ensure that the systems run smoothly and allow you to fix any equipment issues that may arise. It also purifies the water and eliminates any dust that was present in your fish tank.

  • Mature Your Marine Fish Tank

Marine fish do not tolerate ammonia or nitrite well. As such, you will have to mature your tank before you can add fish. Maturing your tank involves the growth in population of useful nitrifying bacteria in your tank filter media. Such type of bacteria will break down ammonia and nitrite to the less toxic nitrate. This process is also known as cycling. 

You have two main options to mature your marine fish tank. You can use a base of cured live rock or bacterial supplements, both of which are commercially available. If you go for the live rock option, spread out the live rock across the entire fish tank creating multiple overhangs and enclaves. You may add any other decorative pieces you like at this time.

Avoid setting live rocks against the tank’s back wall. Take your time to find the arrangement that you like best. Once you have decided on which cycling method to use, you will have to monitor the ammonia, nitrite and nitrate levels. You should expect an initial ammonia peak followed by a nitrite peak. 

These two parameters will eventually drop to safe levels (preferably to zero). The maturation time will vary and requires patience. It can take anywhere from 4 to 8 weeks. Your tank may appear cloudy for a while, but this will clear up through time. 

Once the nitrate and ammonia levels drop to zero, your fish tank is now mature and ready for adding fish. Note that you do not have to have the lighting on during the maturation period. In addition, clean out your filter regularly during this period. 

  • Introduce Fish And Other Organisms

Start by introducing marine creatures that consume algae into your tank first. Hermit crabs and snails are great options as they are hardy and will ensure extra cleaning. After introducing the first marine organisms, wait for at least two weeks before you add anything else.

Clean out your filter every week and test the ammonia and nitrate levels continuously. 

The two-week period between additions allows your marine tank set up to filter and adjust properly. Your aquarium may not adjust fast enough to support the fish if you introduce all of them at once. This is known as the "new tank syndrome" where your filter is incapable of coping with the increased waste load. 

You can now introduce two to three fish species into your aquarium every two weeks until your tank is appropriately full. Always seek advice before purchasing fish, as not all marine species are compatible. You have to be aware of what a healthy fish looks like. 

Large Marine TankLarge Marine Tank

Here are some characteristics of healthy marine fish:

  • Clear and bright eyes
  • Undamaged fins
  •  Intact scales
  •  No bumps or ulcerations
  •  Steady breathing and appropriate swimming

Avoid purchasing seemingly healthy fish in a tank with sickly fish as they can carry diseases without exhibiting any symptoms.


Your marine fish tank is now up and running, and you have to consider its maintenance. There are three main processes in marine aquarium maintenance. These include water testing, water change and finally water replacement.

Water testing  - It is crucial that you test the fish tank water regularly. Your system will stabilize over time, but occasional issues can cause parameter spikes that affect your marine biosphere. The tests include temperatures (around 26 degrees Celsius or 78 degrees Fahrenheit), specific gravity (between 1.023 and 1.025), PH (between 7.8 and 8.5) and ammonia / nitrite levels (zero or near zero).

Water Change  - You also have to change water every two weeks. A water change is where you remove a portion of the water (10% and 20% for small and large tanks respectively) in the aquarium and replace it with fresh saltwater.

Water Replacement - You will have to add water to your fish tank as water evaporates leaving sea salt behind. It is advisable to check water levels 2 or 3 times per week, and add water when needed.


Overall, a fish-only aquarium is a great starting point if you are a beginner. You can easily turn it into a reef tank in the future as you gain more experience. By carefully following the above steps, you will have a complete and healthy marine fish tank.

Now you can sit back and watch in amazement as your marine aquarium comes alive. Keep in mind that marine fish tanks require considerable time to mature. With proper maintenance, you will have a stunning and thriving ecosystem in under 1 year.

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