Saltwater vs Freshwater Aquariums

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An aquarium can be an incredible centerpiece for just about any household, bringing with it a fresh burst of life and color that can easily brighten up the room it is placed in. As an onlooker and potential aquarium owner, it is not difficult to see the appeal. In this article, we will discuss it in the differences between saltwater vs freshwater aquariums.

Of course, as with any undertaking, owning an aquarium comes with its fair share of responsibilities. While fish certainly do not need the same amount of constant care and attention as say, a dog, maintaining their living space requires a considerable amount of attention and effort.

Prospective aquarium owners would do well to consider the number of responsibilities they will have before they commit themselves to anything. These responsibilities begin even before any fish have been bought, and you will need to consider what kind of aquarium you want before you even get a tank. 

Saltwater vs Freshwater Aquariums

Most of the differences that separate saltwater vs freshwater aquariums are fairly obvious at a glance. For starters, saltwater aquariums contain salt, while freshwater aquariums contain no salt (or rather, so little salt as to be virtually undetectable). For your reference, a saltwater tank will have a salt content level of around 34 to 36 ppt, while a freshwater tank will have a salt content level of less than 1 ppt. 

The second primary difference between saltwater vs freshwater fish tanks is in the type of life that they can sustain. Saltwater fish tanks are filled with fish, anemones, and coral that could be found in the ocean, while freshwater tanks are home to a variety of species native to rivers and lakes, including invertebrates such as freshwater shrimp and snails.

None of this should come as any surprise to the prospective aquarium owner. Indeed, for many, the type of aquarium that they choose will largely depend on the kind of fish that they want to display. However, the differences between saltwater and freshwater aquariums extend beyond the species that they can sustain.

There are many disparities between the two kinds of fish tanks relating to cost and maintenance. Both have different requirements for each, which can greatly influence which one you choose. 

When it comes to maintenance, it is generally accepted that freshwater aquariums are much easier to maintain, particularly for newcomers. Freshwater fish – those found in lakes and rivers – have evolved to be resilient under ever-shifting water conditions. This is because rivers and lakes are often susceptible to heavy rainfall, droughts, and floods – all of which can quickly change the condition of the water.

In contrast, saltwater fish do not have the same level of hardiness as their freshwater cousins. The high amount of water in the ocean effectively dulls any rapid changes to its condition, so marine life has been acclimated to fairly constant water conditions. Maintaining a saltwater aquarium, therefore, will require plenty of micromanagement in order to ensure that the conditions of your water are always stable.

Additionally, this leads to the next crucial difference between saltwater and freshwater aquariums. Because of their high maintenance requirements, saltwater tanks cost much more than freshwater tanks. Various pieces of equipment are required in order to properly maintain a saltwater tank, including protein skimmers and powerheads, as well as marine salt and live rock. The fish themselves are also much more costly.

Additionally, saltwater tanks are generally much larger than freshwater tanks. The larger size helps to maintain the condition of the water, but it also makes it much more expensive.

On the other hand, freshwater tanks are small and easy to maintain, requiring little in the way of equipment. The fish tend to be cheaper too.

Finally, the last big difference between saltwater and freshwater aquariums is the variety of fish that they can sustain. The sheer size of the ocean has lent itself to sustaining a huge variety of marine life in different shapes, sizes, and colors. Freshwater fish – while certainly beautiful in their own right – simply do not have the same level of vibrancy as their saltwater cousins.

Both freshwater and saltwater aquariums can be well worth the money so long as you are aware of these differences upfront. 

Freshwater Aquariums

Freshwater tanks are ideally suited to newcomers due to their low cost and level of maintenance. Freshwater fish can be found at pretty much any pet store, and the tanks themselves come in a huge variety of shapes and sizes to accommodate all needs and wants. 

Going in, you will need to consider the initial setup costs including gravel, lighting, plants, and of course the fish themselves. Beyond that, you will also need food, electricity, and a water conditioner.


  • Easy to maintain, ideally suited toward beginners
  • Plenty of options in terms of shape and size, accommodating all tastes
  • Low cost, both in the long-term and upfront


  • Smaller variety of fish available
  • No coral reefs, which could have brightened up the tank even more
  • Complacency due to the ease-of-maintenance
Saltwater vs Freshwater Aquariums

Saltwater Aquariums

Saltwater tanks can sustain a wide variety of fish and can make for some truly impressive, beautiful displays. However, they also require constant care and maintenance in order for them to sustain life in the long term, making them better suited towards long-time aquarium owners.

There are plenty of costs to consider going in. The tank itself will most likely be very pricey, and the equipment required to get it running properly will set you back quite a bit as well. The fish, too, are known to be quite expensive.


  • Colorful, gorgeous fish
  • Unique species of invertebrates
  • Wide variety of species is available


  • Expensive to buy and maintain
  • Huge tanks require even more maintenance
  • Sensitive environments that require constant vigilance
  • Extra care with the nitrate levels


As mentioned, for long-time aquarium owners the tank that they choose will most likely depend on the fish that they want to keep. For beginners, however, it is highly recommended to start with a freshwater tank due to its low costs and the low level of maintenance required to sustain it.

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