Butterfly fish

How To Set Up A Saltwater Aquarium

This step by step guide is for anyone interested in learning how to set up a saltwater aquarium. A saltwater aquarium doesn't have to be difficult. It just takes some effort on your part to learn about and research the necessary topics in order to have a good saltwater setup. Let's get in to it.

How To Set Up A Saltwater Aquarium

What do I need to start a saltwater aquarium?

Well, for the type of saltwater fish tank setup (marine aquarium) described in this article check out the checklist below for the equipment needed.

  • Saltwater Aquarium
  • Aquarium Photo Background or Paint the background - see Aquarium Aquascape Design for more info on painting the tank background.
  • Aquarium substrate for your saltwater aquarium setup such as live sand or crushed coral
  • Live Rock - provides food, shelter and filtering capabilities
  • Saltwater Mix
  • Saltwater Hydrometer or even better a refractometer
  • Aquarium filter (not absolutely necessary if running with adequate amounts of live rock, but nice to have if you need to use a mechanical filter or activated carbon, etc.)
  • Replacement filter media like filter floss and activated carbon (if you get a filter)
  • Multiple power heads (2 or 3)
  • Heater - be sure to get one large enough for the size tank you're getting
  • Protein Skimmer - See the equipment reviews section for protein skimmer reviews
  • Saltwater test kit(s) to test water parameters and monitor the infamous aquarium nitrogen cycle
  • Saltwater fish food
  • Aquarium vacuum
  • Fish net
  • Aquarium gloves
  • Aquarium Glass Scrubber or make your own DIY Algae Scraper
  • Two, clean, never used before, 5-gallon buckets
  • Aquarium thermometer
  • Brush with plastic bristles (old tooth brush) - needed for cleaning the live rock
  • Quarantine Tank for acclimating new arrivals and monitoring for signs of fish disease
  • Power Strip
  • Optional but definitely recommend getting a Reverse Osmosis Filter or RO/Deionization filter for the make-up water.

Cost is another very serious factor. Take the list above and research the prices of the various equipment needed to setup a saltwater fish tank. You will soon realize that a saltwater aquarium can cost significantly more to purchase than a freshwater aquarium setup. Not to mention that saltwater fish are usually more expensive that their freshwater counterparts.

You also need to understand that setting up a saltwater aquarium takes time. It often takes 4 to 8 weeks before you can add any marine fish safely to your saltwater aquarium setup.

Decide on an aquarium size and location

It's a good idea to know what kind of saltwater fish you want to keep before you purchase your aquarium. Do a lot of research on the various types of marine fish to determine which fish you would like to get. Some marine fish only grow to be an inch or two, whereas other types can grow to 12 or 18 inches! Knowing what kind of marine fish you want will help you decide the size of the aquarium they will need.


Below are some of the most poopular saltwater fish species profiles here on FishLore. Read them to get an idea on the proper aquarium size to get started with.

Centropyge loriculus
Dwarf Flame Angelfish

Centropyge bispinosa
Coral Beauty Angelfish

Gramma loreto
Royal Gramma

Chelmon rostratus
Copperband Butterflyfish

Pterapogon kauderni
Banggai Cardinalfish

Amphiprion ocellaris
Ocellaris Clownfish

Acanthurus leucosternon
Powder Blue Tang

Zebrasoma flavescens
Yellow Tang

Chromis viridis
Green Chromis

Synchiropus splendidus
Green Mandarin

Many books stress that you shouldn't get started in the saltwater hobby unless you have at least a 40 gallon. But if you've done your research and thoroughly prepared, there is no reason why you can't start with a smaller tank. Be warned, a smaller tank will pose more challenges and will force you to perform more frequent water testing and maintenance.

You will want to place your aquarium in an area where the light and temperature of the tank won't be affected by external sources such as windows and heater vents. You will also want to place your aquarium on a stand that will be able to hold its total weight. A good rule of thumb for determining the total weight of a full aquarium is 10 pounds per gallon of water. For example, a 55-gallon tank will weigh approximately 550 pounds when filled with water only! You also have to account for the total amount of live rock, sand and equipment.



Buy your aquarium and equipment

Sometimes you can find some really deals on complete saltwater aquarium kits whereas other times it is better to buy the equipment individually. Now is the time to decide on the type of filtration you will want to use when you setup your saltwater aquarium and the type of protein skimmer. We do not recommend using an undergravel filter. An undergravel filter is not needed and will only cause you headaches down the road. Since we will be using live rock as our biological filter, you really only need a modest filter for the mechanical and chemical filtration. Don't skimp on the protein skimmer. After the live rock, the protein skimmer is probably the next most important piece of equipment. When it comes to protein skimmers you really do get what you pay for. We have posted a few protein skimmer reviews and there are many more out there. Listed below are skimmers that we have reviewed:


Octopus 800s Protein Skimmer - *Very good skimmer
Octopus 200 NW Protein Skimmer Review - *Very good skimmer
AquaC Remora Protein Skimmer - *Very good
Tunze Nano Protein Skimmer - *Very good
Hydor Slim Skim Protein Skimmer - *Ok skimmer
Red Sea Prizm Protein Skimmer - *Ok, needs frequent adjustments
Fission Nano Protein Skimmer - *Don't waste your money
Visi-Jet-PS Protein Skimmer - *Don't waste your money

You will also need to purchase a heater capable of heating the aquarium size you have.

Get the live rock, sand and a power strip. Try to get 1 to 2 pounds of live rock per aquarium gallon. One rule of thumb for the amount of sand that you will need is about 1/2 to 1 pound of sand per gallon of water. Don't use sandbox or playground sand because it can have various unknown particles that may be harmful to your fish. Get either live sand or an aragonite based sand (from caribsea) or crushed coral.

A recent development in the past year or so has been biopellets. These are small polymer based bio-degradable pellets (biopellets) that as they slowly break down in your reactor will begin to feed and grow bacteria that will consume nitrates and phosphates thereby lessening the growth of undesirable algae forms your tank. You have to use a skimmer to get the full benefit of using biopellets and you need to direct the flow from the pellet reactor into the skimmer so that the excess "gunk" (or whatever the waste products of the pellets is called) is skimmed out of the system. Setting up a biopellet reactor will set you back about $100 dollars or so but it is well worth it, especially if you are fighting algae problems in your display tank. For more information or to get started, check out the biopellet article.


Set up your aquarium, stand and equipment

Wash out your tank with water only! Do not use soap or detergents. Soap residue left behind will be harmful for your saltwater fish. Smoke test your aquarium by filling it with fresh water and check for leaks. If it passes the leak test, drain the fresh water from the aquarium.


Affix your background at this time. Be sure to use tape all across the top back of the background to prevent any salt creep from getting in between the background and tank glass. Alternatively, you can also paint the back tank glass (paint the outside back, not the inside). Painting the back glass can be better than using a background because you won't have to worry about salt creep making its way in between your aquarium background and the back glass. For marine tanks, a black background can help the fish colors stand out more. Deep blue is another popular color choice and it can help create the illusion of depth. After painting, let the tank sit for a day or so to allow the paint to dry.

Install your heater, hook up your filter, protein skimmer and any other equipment you have and be sure to use a drip loop on all of the power cords. For more safety tips, read the aquarium electrical safety article. Don't plug in anything yet!


Add pre-mixed saltwater to the aquarium

All of the marine salt mixes out there are made slightly differently. There is much debate as to which salt mix is the best. Here is a comparison on some of the available saltwater mixes. Unless you're considering a reef tank, most of the commonly available mixes should serve you fine. You'll soon develop a salt mix preference after you've worked with them for a while.


Use a clean 5-gallon bucket to mix the saltwater. First fill the bucket and then remove the chlorine and chloramine. Use something like Tetra AquaSafe for Aquariums. Read the directions on the salt mix package carefully and then add the salt mix slowly to room temperature water. Stir it well and test it with your hydrometer or refractometer. Once you get a specific gravity reading between 1.021 and 1.024 you can add the saltwater to your aquarium. Repeat this process until you have filled your tank. If you have a large aquarium you can mix the salt in the tank. Mixing in the tank can be more difficult and messy, so just be sure that you have thoroughly dissolved all of the salt mix before using the hydrometer.

Turn on the aquarium and let the water circulate for a day or two.


Cure the live rock

Live rock is probably going to be the greatest expense with the initial setup of a saltwater aquarium. For a reef tank setup it may be the aquarium lighting. For this reason, you are probably going to treat your live rock like gold once you get it. However, even though it can cost a lot of money, it will probably end up saving you money (in fish) because it is the best form of biological filtration. The curing process can last anywhere from 1 week to 2 months or more depending on the shape the rock is in when you get it.

Drain some of the aquarium water and then place your live rock in the tank. Try to place it in the middle of the tank and aim the power heads (you should have 2 or 3) at the live rock. Placing the live rock in the middle of the tank will allow you to siphon up the debris that the power heads will be blowing off.

Every few days turn off the power to the tank so you can perform live rock maintenance. Use some new rubber kitchen type gloves while doing this to protect your hands and the rock. You will need to scrub the live rock with a brush that has plastic bristles (old tooth brush) to remove any obviously dead or dying organisms. You can do this directly in the tank. Siphon up the debris and then refill with pre-mixed saltwater. The day before you perform the live rock maintenance get your saltwater ready. If you have a smaller tank you can use a couple of 5-gallon buckets for this purpose. If you have a larger tank you may want to invest in a large rubber trash can for pre-mixing your saltwater. Whatever you use, you will need to place a power head and a heater in the pre-mix container so that the mix dissolves correctly. Test your water throughout the curing process to determine if the tank is cycling.

During the curing process your tank may smell pretty bad and a good indication that your live rock is cured is when it no longer smells bad but more like the ocean. Use your test kits to verify that the tank has indeed cycled. You should have 0 ammonia, 0 nitrite and some sort of reading on the nitrates.


Add your substrate

First, drain some of the saltwater in your aquarium to allow for the sand you're about to add and turn off the power to the tank. We'll use the 5-gallon bucket to clean the sand. Use the 5-gallon bucket to pre-mix about 2 gallons of saltwater. Add your sand to the bucket and then stir. This will allow some of the dust and dirt to rise so you can then siphon it off. Drain some of the saltwater from the bucket before adding your substrate. Use a plastic cup, ladle or something similar to add the freshly cleaned substrate to your aquarium. Use one of your power heads to blow off any sand that gets on your live rock during this process.


Allow the tank to settle for a few days

Monitor your water parameters closely during this time. Check the salinity or specific gravity, pH, ammonia, nitrite, nitrate and carbonate hardness levels and correct as necessary. Ideally, you want the following readings for your saltwater tests before you start adding fish to your saltwater aquarium setup:


  • temperature: 75°F - 80°F (24°C - 27°C)
  • specific gravity: 1.020 - 1.024
  • pH: 8.0 - 8.4
  • ammonia: 0
  • nitrite: 0
  • nitrate: 20 ppm or less (especially for invertebrates)
  • carbonate hardness: 7-10 dKH


Slowly add saltwater fish after the tank has cycled

I can't stress enough the need to use a quarantine tank for any new marine fish. You are playing a game that you will eventually lose by adding fish directly into the main tank. For more information on using a quarantine tank.


Only add one or two saltwater fish at a time. Only adding a couple saltwater fish at a time gives your filtration system the time needed to take on the increased biological load that the new fish introduce. When bringing home new saltwater fish, the acclimation process is a little more involved. Dump the bag contents (fish and water) into a clean 5-gallon bucket and then add about 1 cup of aquarium water to the 5 gallon bucket every 10 minutes. Continue to add 1 cup of aquarium water to the 5-gallon bucket every 10 minutes. After an hour or so your marine fish or invertebrate should be ready to add to the aquarium (qt tank). Following this more involved acclimation process will help reduce the amount of stress imposed on the saltwater fish. Stressed fish often leads to dead fish! Don't feed your saltwater fish on the first day. They probably wouldn't eat any food on the first day anyway. Let them get acquainted with their new home.


Perform Regular Aquarium Maintenance.

Be prepared to spend some time every day to monitor the temperature and salinity levels on your newly setup marine aquarium. You will also need to spend some time once a month to clean your tank and change out some of the saltwater. Try to change 20% of the saltwater in a given month. This could work out to doing small 5% water changes once a week. Performing regular small water changes will reduce the nitrate levels, replenish elements that have been used up and skimmed off and keep your saltwater fish happy and healthy. Remember to never add freshly mixed saltwater to your aquarium because it is fairly caustic freshly mixed. Mix it up the day before you will be doing maintenance.


If this has helped you then please leave a comment below, thank you Fish Tank Keepers.


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