Aquariums for Beginners — Freshwater or Saltwater?

If you’re thinking about setting up an aquarium, one of the first decisions is deciding whether the tank should be freshwater or saltwater. Both aquarium types have a wide range of beautiful fish available, but each have their own set of challenges and considerations.


Before setting up an aquarium, there are two important factors to consider – cost and commitment. Freshwater aquariums are usually less expensive and easier to maintain than marine tanks, but it also depends heavily on which fish you intend to keep. The best place to get advice on specific combinations of species is your local aquarium store – though our fish wiki is pretty awesome, too.

Equipment Requirements

Even the most basic fish tank requires some equipment. A freshwater tank will require;

  • A fish tank
  • Lighting
  • Filter
  • Water conditioner (if using tap water)
  • Heater (unless you’re keeping Goldfish)

If you intend to keep saltwater fish, the needed equipment list grows substantially. In addition to the above, the most basic marine aquarium would require:

  • Salt
  • Hydrometer, or some other salt-measuring apparatus
  • Specialized lighting

The Fish

The unrivaled beauty and diversity of marine fish attract the attention of many newcomers to the hobby. Unfortunately, those who jump straight into saltwater species often experience disappointing results. There are just too many water quality, diet and compatibility challenges for the average novice to handle. Marine fish are usually more expensive and difficult to source than freshwater species, presenting yet another argument against keeping them. Unless you’re absolutely sure you have the time and experience to ensure their care, sticking with freshwater fish is strongly recommended.


Freshwater and saltwater aquariums both require frequent cleaning and monitoring to maintain high water quality. An aquarium is a small area and is typically more densely populated with fish than a natural habitat. Subsequently, it is important to provide frequent and regular water changes to limit the buildup of harmful toxins. In an average tank, 50% of the water should be replaced in any given month. If water is to be replaced with tap water, it must first be treated with a water conditioner. Larger tanks, or tanks with lots of live plants, can generally tolerate less frequent or aggressive water changes.

In a saltwater aquarium, new water must first be tested to ensure that it has the right salt density and temperature before adding it to the tank. It can take some time for the salt to dissolve fully into the water. Because of these extra steps, water changes are substantially more time consuming for those who wish to keep saltwater fish.


Freshwater fish require somewhat less maintenance than those who prefer salt water, so are strongly recommended for beginners. Having said that, the spectacular colors of saltwater fish make them a worthwhile and rewarding challenge for those who have the time and the experience to care for them.

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