There are many reasons for setting up a saltwater aquarium, not least of which is its beauty. The beautiful colours of fish and coral, interesting algae, soothing sound of bubbling water and the fun involved in creating a fabulous marine world are all reasons why keeping saltwater aquariums gives people so much fun and pleasure. 

Saltwater aquariums are not for everybody and even the simplest marine tank can cause headaches. Fish keeping can be tricky and marine fish in particular take a lot of time and effort to keep healthy. 

This is because marine species are far more sensitive to water quality and temperature changes so you will need to be informed about the needs of all your fish as well as the tank itself. Saltwater aquariums require patience and a degree of know-how to make it work. You will also need to make sure that you can afford to keep the tank in a healthy state. 

Which saltwater aquarium you choose will depend on your aims for the tank and your personal preferences. There are many different options available in terms of the fish and animals you can keep in your tank as well as the equipment you can choose from.  

The first thing to decide when setting up saltwater aquariums is what kind of fish you want to keep. The next step is finding out as much about each one as you can.  

There are two main kinds of saltwater aquariums namely 1) ‘fish only’ or 2) ‘fish only with live rock’ OR ‘reef tanks’. 

The first is probably the easiest saltwater aquariums to attempt. This is because in saltwater aquariums of this nature, lighting is not really an issue and you can use a simple tank with its usual equipment and only a few extra bits like protein skimmers, powerheads and live rock or sand. 

These kinds of saltwater aquariums will usually be either a community tank containing species like clownfish, damselfish, gobies, wrass, and dottybacks, or an aggressive tank where you will find species like lionfish, triggers, eels, groupers, and larger predatory species. 

Before you choose your fish, make sure you know EXACTLY which species live well together to avoid your tank turning into a complete massacre. If you are a novice to saltwater aquariums start with a tank that is at least 10 gallons in size. This is because most if not all of your fish will easily outgrow the tank. 

Go for the largest tanks you can afford. The bigger saltwater aquariums are easier to keep in tip-top shape. 

Most important to the health of saltwater aquariums is water purification in your tank. This means that even the smallest amount of impurities in the water can hurt your fish Remember most of these animals are found in natural coral reefs where the water is very pure. So, you will need to make sure that the water in your tank is clean at all times. 

In small (10 gallons) saltwater aquariums you can use a Brita filter or water purifier column or you can use distilled water. These methods won’t work in bigger tanks, however. The best bet for any size tank is an RO/DI (reverse osmosis/deionization) system. 

Filtration is quite complicated in saltwater aquariums but depends to a large degree on the fish species you intend to keep and how many. In a fish only tank you can use a freshwater filter for example canisters, power filters and the like. You can also try a wet-dry trickle filter.   

Protein skimming is also important in saltwater aquariums and it is strongly recommended that you do it, especially if you have lots of fish in your tank. A protein skimmer uses foaming bubbles to separate fish waste that floats up to the water column from the water’s main flow. 

The foundation in your tank will require the laying down of live sand. In saltwater aquariums sand doesn’t only act as a substrate it is also the breeding ground for millions of vital bacteria. These bacteria help the nitrogen cycle to work efficiently. The sand is also home to the small animals that help control the waste products in your tank. 

The best sand for saltwater aquariums is calcium carbonate (aragonite). You can get this from crushed corals, or finer sands. You can also use silica and quartz sands but they are not as good. 

Probably one of the most expensive features of saltwater aquariums is live rock but prices may put off many a budding marine aquarist. Live rock can be bought by the pound and it is expensive because it’s the real thing. In the sea live rock makes up a reef structure with little calcium carbonate structures produced by corals. Since live rock is harvested from nature and laws govern this harvesting you can begin to understand why it is so expensive. 

Live rock is important to saltwater aquariums for the bacteria it introduces into your tank. These little organisms keep your water filtered in the same way it does in nature. It also acts as a home and shelter for your fish and a place for coral to grow. It is well worth the high price you pay.  ‘Fiji’ rock is a good choice if you can find it. Try to avoid any live rock that has a mantis shrimp on it as they multiply very quickly. 

Remember you will still need to cycle your tank and perform the necessary water quality testing before you add any of your livestock. So, there you have it – the basics of what to start thinking about as you set up saltwater aquariums.