Freshwater vs Saltwater Fish Tank: The Aquarium Ultimate Guide

Are you debating whether to get a freshwater vs saltwater fish tank? A planted freshwater aquarium or a stunning reef tank can both be rewarding, but they each have their own unique challenges.

You’ll typically find that the most popular fish are housed in freshwater tanks with a variety of plants. On the contrary, saltwater aquariums tend to have much more colorful or exotic fish, as well as UV lights, coral, and rocks for decoration.

Building an aquarium for your home can be a truly amazing experience, regardless of which type of tank you choose. In this post, we will go over everything you need to know to understand the difference between saltwater vs freshwater aquariums.

Once you understand the basic differences between freshwater and saltwater aquariums, you’ll be able to make an informed decision on which aquarium is right for you.

Saltwater Aquarium Basics

Saltwater aquariums offer a unique way to bring the beauty of the natural aquatic environment into your home or office. The saltwater reef aquarium, in particular, is very popular because it is so colorful and interesting to look at.

However, setting up a saltwater aquarium requires special considerations, such as the type of substrate used on the bottom of the tank, the lighting system to help live coral grow, and careful control of water parameters like temperature and pH levels.

For example, saltwater livestock is considerably higher in cost than freshwater. Plus, reef tanks are usually larger than freshwater tanks, and they are harder to take care of because the water parameters change more often.

Because marine life has evolved to survive in relatively constant water conditions, keeping a saltwater aquarium without frequent water changes is critical.

Larger aquariums with marine salt content will generally require more time when it comes to tank maintenance, such as water testing, topping off water, and replacing the filter more often. As a result, maintaining saltwater aquarium environments will take more time and money.

Freshwater Aquarium Basics

Freshwater aquariums also called “tropical aquariums,” are less precarious to maintain. They come in a wide variety of sizes, and they are a great option for your first aquarium setup. These aquariums will generally be suitable for tropical fish species like Bettas, Gouramis, Goldfish, Barbs, Corydoras, and more.

The saltwater aquarium vs freshwater aquarium cost varies significantly. Freshwater aquarium owners spend less than three hours per week on maintenance tasks such as cleaning, testing, changing water, and monthly filter maintenance.

Compared to their saltwater counterparts, freshwater fish are stronger and can withstand greater variations in water parameters. Depending on the species, you can buy one of these fish for as little as $5 to $10.

As far as the setup cost, you can purchase a kit that includes the freshwater tank, gravel, plants, lighting, and filter system. Once you have determined the size of the tank, the setup cost will depend on the type of tank, the size and number of fish, the type of filter, and other decorations.

Saltwater vs Freshwater Aquarium Main Differences

Before purchasing and setting up a new fish tank, it’s important to do your research so you can make sure that the type of tank you choose is best suited for your needs. Ultimately, deciding between saltwater and freshwater aquariums comes down to personal preference.

When starting a new aquarium hobby, the first decision to make is whether to go with a freshwater or saltwater aquarium. Here are some of the things to evaluate:

#1 Type of Aquarium Based on Tank Size

There are many different kinds of tanks, from those that can hold a single Betta fish in a gallon tank to 350-gallon reef aquariums that can hold hundreds of fish. For optimal results, a saltwater aquarium should be at least 30 gallons in size.

Inconsistent water quality becomes more problematic in smaller tanks, making it difficult to house marine systems. If you want to build your own custom aquarium, you should talk to an expert in marine biology to make sure the tank is set up to keep the fish healthy.

#2 Aquarium Maintenance Cost

In terms of cost, freshwater aquariums are usually more affordable than saltwater tanks since they require fewer pieces of equipment. However, if you’re looking to own a larger variety of marine species, then saltwater aquariums may be the best choice for you, as there are many species that only live in salt water.

Saltwater setups require a significant investment in terms of time, money, and effort. Most saltwater fish come at a higher cost than freshwater fish (hardy fish), and they require additional equipment such as protein skimmers, canister filters, live rocks, wave makers, and more.

#3 Type of Aquarium Water Used

Rivers, lakes, streams, and ponds are the original habitats of the fish kept in freshwater aquariums. You can use tap water for your freshwater tank as long as you use a dechlorinating agent to remove the chlorine and other impurities from the water.

Water quality should also be monitored on a regular basis, as different fish require different conditions to stay healthy. You need to keep an eye on the temperature and the ammonia levels to make sure your fish are living in a safe and healthy environment.

Most pet shops sell salt for marine aquariums that you can add to your tap water to achieve the same levels as seawater. You may also need a hydrometer to measure the specific gravity of your tank water.

#4 Aquarium Equipment, Plants, and Other Items

Saltwater tanks need more equipment than freshwater tanks. Aquarium enthusiasts use protein skimmers in conjunction with filters to remove organic waste from their tanks.

They also tend to include a live rock in their reef system so that the beneficial bacteria living within the rock can help break down ammonia, nitrite, and other pollutants. It’s possible that the number of hours and intensity of lighting will need to be changed if you add a beautiful coral.

Your freshwater tanks will need an air pump and thermometer to ensure the water temperature and oxygen levels stay consistent. If you want to add live plants, you will need to buy more lighting and plant food.

Which one is less expensive: a freshwater or saltwater aquarium?

Generally speaking, freshwater aquariums are less expensive than saltwater fish tanks. This is mostly because freshwater aquariums need less special equipment and items than saltwater aquariums.

For instance, a freshwater tank may only require a filter and some decorations, while a saltwater tank may need more items, such as a protein skimmer, an ozone generator, and live rock.

Which one is harder to maintain: a saltwater aquarium or a freshwater aquarium?

Freshwater aquariums are much easier to maintain and set up as compared to saltwater aquariums. The main difference between the two is that freshwater fish require less costly equipment and can live in tanks with lower levels of salinity.

Saltwater fish need more specialized tanks that have higher levels of salinity and need more filtration systems, which can be costly. Definitively, saltwater environments are much more expensive to maintain than freshwater ones.


Is owning a saltwater aquarium easier for a beginner?

No. A saltwater aquarium is much more complex, and the cost of setting up such an aquarium can be significantly more expensive. The size of the tank you need is also larger than that of its freshwater counterparts, making it even more costly.

Saltwater aquariums require more maintenance as well, as special equipment and chemicals will need to be regularly purchased in order to keep the tank’s water chemistry balanced. If you are just starting out, it is recommended that you choose a freshwater one instead.

Can a freshwater fish survive in a saltwater tank?

Most freshwater fish species cannot survive in saltwater or seawater because of the high concentration of salt. Osmosis will draw the freshwater out of their cells, causing them to dehydrate and ultimately die. They can only survive in freshwater environments that contain low levels of salt, where they can maintain the correct balance of water and electrolytes in their cells.

Can a saltwater fish survive in a freshwater tank?

No, due to the high concentration of salt in their bodies, saltwater fish cannot live in freshwater environments. In a freshwater environment, water would seep into fish bodies until all of their cells accumulated so much water that they eventually bloated and died.

Most saltwater species require a “marine fish only tank” or saltwater tank. There are some marine fish that can be kept in a small saltwater aquarium due to their adaptability, such as dwarf angelfish, ocellaris clownfish, and some gobies.

Last Freshwater And Saltwater Aquarium Tips

Both a freshwater aquarium and a saltwater aquarium have their own advantages and disadvantages. Compared to freshwater aquariums, saltwater aquariums require more maintenance and care.

Ultimately, the decision about which type of aquarium is best for you depends on your own preferences and resources. Here are some tips to remember:

  • Determine the maximum amount of fish that can live comfortably in your aquarium.
  • A saltwater aquarium is a lot more complex and requires significantly more resources.
  • Choose the type of fish that will be most suitable for your particular environment.
  • A large tank is essential if you want to add brightly-colored fish and coral to your aquarium.
  • Keep freshwater species away from seawater because they come from bodies of water.
  • You would have fewer colorful fish if you decided to go for a saltwater tank.
  • Saltwater-only fish would not survive in a freshwater environment, and vice versa.

Both freshwater and saltwater tanks can be beautiful and rewarding environments for fish if done properly. Whether you choose saltwater or freshwater is largely based on the type of fish you wish to have, the experience level of the owner, and the amount of maintenance they are willing to invest.

Last Updated on 23/01/2023 by Karen Snow