A Beginner’s Guide To Setting Up A Saltwater Tank

saltwater tank

Setting up a saltwater tank is usually an upgrade from freshwater tanks for many, but it is not necessary. Just a bit of understanding, practice and patience goes a long way in being a successful saltwater tank hobbyist! This article is not a complete checklist, but a guide to help you through the process.

Saltwater Tank Type

Saltwater hobby can be divided into 2 sub categories namely FOWLR (Fish Only With Live Rock) and REEF (Fish, Corals, Inverts Etc.). Deciding on what to choose is a big one. Especially because of the time, cost and space involved. However, let me tell you that a FOWLR tank is perfect for beginners as you wouldn’t have to deal with most of the super-sensitive marine creatures that you would put in a full blown reef tank. This gives you a slight buffer and helps you realize what it takes to be consistent in the hobby. This though, doesn’t mean you have a lot of room for errors.


A FOWLR as mentioned earlier only consists of fish and live rocks. Do note that live rocks play a very important role in keeping your system healthy. We will read more about it below. In a FOWLR tank, the live rock would be your main source of filtration in addition to any filter media you put in your filters. FOWLR tanks usually require lesser amount of salinity than reef tanks, so if you plan on setting one up, you also save on salt. Some inverts like snails, some varieties of shrimps and hermit crabs can be kept in a FOWLR too.


A reef tank consists of many different creatures ranging from reef friendly fishes to anemones, corals, sea cucumbers, shrimps, snails and many more. As this article is more towards helping beginners, we won’t go much deep into reef tank right now. Do note that reef tanks cost almost double of what a FOWLR would cost. This is because of the added amount of live rock, filtration, salt as well as the cost of the livestock itself. Reef tanks require a lot of research before one can jump onto it. In addition to the above, we would also request you to research on the type of fish you choose for a reef tank. Many varieties of fish are simply not going to do well. They would nip at your corals and kill them.

Want to know what suits your tank the best? Read Best Saltwater Fish For Beginners 

Tank Size

As the rule says, bigger the better. There are many pros to have the biggest tank that fits your space and budget. You get more space- more fishes! You get more buffer- smaller tanks have very low margin of error. One small mistake and your tank is dead! Larger tanks = more stability in your water chemistry, temperature etc. Trust us, a bigger tank will go a long way. Coming to the smallest tank, we would suggest nothing below 30 gallons for any fish. A 30-gallon tank will be a good start for small fishes like a couple of Ocellaris Clownfish/ Firefish/ Gobies etc. Also remember, longer and wider tanks are always better than taller and narrower tanks. Most fish are elongated in shape and swim from front to back not up and down. So remember, a tall tank doesn’t necessarily mean a large tank in terms of space!


Saltwater tanks are not as easy to maintain as freshwater. This is not to discourage you but to make you aware of the fact that water sources from tap or well are simply not recommended. Take our word for it or you would have a hard time later on! The best source of water for your fish tank would be RO. RO (Reverse Osmosis) water goes through special membranes that removes ions and molecules. The main reason to use such pristine water is because saltwater fishes are extremely sensitive even to the most minute changes in water chemistry. One small error and it becomes fatal for them. If you read the composition of leading fish tank salts, you will see the number of additives in it to keep your tank as close to nature as possible.

Tap water contains a lot of hardness, impurities, chemicals and silicates that harm a saltwater tank. You also need consider the amount of water that evaporates every day and remember to replace it with ‘fresh’ RO water as salt does not evaporate! Investing in an RO unit is very good for this purpose.


Filtration is not very difficult in a FOWLR tank. Live rock is usually considered the main filtration system in a FOWLR. Live rocks are not live themselves but in fact, house millions of beneficial bacteria and various tube worms, feather dusters etc. that help clean the tank water naturally. Do note that you need enough rock to sustain a healthy filtration system. 1-1.5 Lbs per gallon of tank water is a good way to go. Protein skimmers are also good for a filtration system but its use in a FOWLR is debated upon.

For reef tanks however, it is much more complicated. Contrary to a FOWLR, a protein skimmer is a must in reef tanks. Reef tanks house numerous corals and other sensitive life that need pristine water quality. A protein skimmer helps remove organic waste from water column that passes through the mechanical media without being filtered. These types of wastes are usually dissolved. They contain fish poop, urine, dead algae, nitrogenous waste etc. Always plan on choosing a skimmer rated for double the size of your aquarium. It would have to work less and will go a long way. There are other filtration systems like the algae scrubber, bio-pellet reactors and many more.

Equipment and Supplies

Lighting –

If you choose to have a FOWLR tank, lighting won’t be much of a hassle. As with common freshwater tanks, lights do not make any difference to a fish only tank. Live rocks also don’t need light as much as a reef tank would. A normal T5 blue/ white light would suffice. For better efficiency and power, you could go with LEDs. LEDs are very customizable so you get what you pay for.

For Reef tanks however, very strong lighting is required. Corals require a very high PAR lighting. If you plant to keep a reef, please research more about lighting requirements as each type of coral or anemone require very different lights. Too much and you would bleach them white, too little and you would cause algae growing on them.

Flow –

Oceans have lots of current and fishes have evolved to be in such rough conditions. It is important for us to provide good amount of flow to them so we can replicate their natural surroundings. For smaller tanks, normal filter output or a power head would create enough flow for your fish to play in. But in larger tanks, it is better to put a few wavemakers that would create realistic ocean currents right inside your tank! For FOWLR tanks, aim to create currents/ flow 10 to 20x the size of the tank. So for a 30 gallon you would buy a wavemaker/ powerhead that is has an output of at least 300-600 GPH. For reef tanks, 20x is a minimum. Furthermore, you should make sure you give enough surface agitation to break any protein film formed over time and to oxygenate the water well.

Water Testers –

There are a few testing supplies you absolutely cannot go without regardless of the type of tank you plan to keep. A hydrometer/ refractometer, pH tester and Ammonia tester are absolutely must. A hydrometer helps us get the salinity of the water. Average FOWLR tank salinity ranges from 1.021-1.023 and 1.023-1.025 for a reef tank. FOWLR tanks can get away with a good quality hydrometer, but we suggest on getting a refractometer for reef tanks. Refractometers are much more accurate and can be calibrated easily. Hydrometers at times are way off limits, so much so, that it can wipe out even the most basic FOWLR tank.

Constant check on ammonia is also very important. Ammonia readings can help test our filtration. Even traces of ammonia can wipe out a tank and indicate a problem with the filtration system. pH readings help to analyse the pH of the water. Good quality salts will have pH buffers in it but still, a pH meter comes in handy.

Heaters –

If you live in a country with cold winters, you might want to invest in a good quality heater that keeps your tank temperature stable. Do not go for cheap one’s as they might crack or fail anytime and not only kill your tank but may also cause a fire if it shorts. You may need around 2.5-3Watts per gallon rated heaters. Hence you would need a heater rated at 70-90 Watts for a 30 Gal. tank.

Substrate –

You can either choose to have a substrate or go bare bottom. This is a very personal preference. Some feel bare-bottom tanks reduce the risks of algae or excess bio load whereas others feel it helps in filtration and gives a natural look to the aquarium. We leave this up to your own preference. If you choose to add a substrate to the aquarium, you can go with ‘live sand’ or normal pool sand. ‘Live sand’ is normal aragonite sand mixed with beneficial bacteria. This helps cycle the tank faster. It costs higher and we feel it has no added benefits for its high price. You can easily supplement this with a good quality bottled bacteria.

One pro of keeping a barebottom would be if you choose very high quality corals like SPS or some types of LPS that require insane amounts of flow. You would be better off going barebottom than having a sand-cyclone in your tank every now and then. (What would happen if your wavemaker suction fails?)

We hope we could explain the main points to consider before getting a saltwater tank. You are free to research more about each of the points given above for a better understanding. Never rush with your decisions and give your tank time to settle! Don’t hurry!
Happy fish keeping 🙂

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