Did you know that over 7.2 million households keep fish as pets? After dogs, cats, and birds, fish are the fourth most preferred pets worldwide. Are you surprised? You shouldn’t be. Fish are smart pets. They can socialize and are playful. With their jolly nature and vibrant appearance, they surely can steal anyone’s heart.
There are a variety of fish aquariums, but saltwater and freshwater aquariums are the most popular ones. Often, choosing one of them becomes a confusing task to accomplish. Both come with so many advantages and disadvantages that you might find yourself in the middle of nowhere!
This article is intended to present a crystal clear comparison to clear all your doubts regarding saltwater and freshwater aquariums.
Without any further delay, let’s jump straight into the article.
Saltwater Aquariums: Plunging into the Ocean
Saltwater aquariums are miniature models of the ocean ecosystem. They are often known as reef aquariums. The fish of the saltwater aquariums particularly thrive in the oceanic environment. The saltwater aquariums, also known as marine aquariums, often offer beautiful fish with captivating color combinations along with corals and other underwater organisms.
It is often said that these types are pretty hard to keep. You may have come across a common dialogue in this context that “Beginners should not start with a saltwater aquarium.” Is that true? Is it impossible for you to start a marine aquarium if you are a newbie?
We are going to discuss that soon. Stay tuned.
Freshwater Aquariums: The Green Tank
Freshwater aquariums are the most famous ones among beginners. They are the smaller replicas of the tropical water bodies with lots of plants in them. They are less colorful compared to their marine counterparts. It is primarily believed that these types of aquariums are relatively easy to maintain. Well, that might or might not be accurate. We will get to that very soon.
Saltwater vs. Freshwater Aquarium:
Now that you have a basic knowledge about saltwater and freshwater aquariums, you must be wondering which one you should choose. Well, we are here to help. There are some charming advantages as well as repelling features to both of them. Let’s get into the comparison section to have a clearer idea of these.
We proceed with our discussion on the following points.
1) Tank size:
Freshwater aquariums are relatively flexible when it comes to size. You may set your freshwater tank in smaller sizes. You can opt for a ten-gallon or twenty-gallon tank if you are new to the fish world. The aquarium can be made of glass or acrylic.

Marine aquariums are not supposed to be set up in a size less than 30 gallons. The smaller tanks are pretty hectic to maintain. The subtle change in your marine fish tank can kill or severely harm your colorful friends.
2) Water Conditions:
The water conditions of both the tanks are starkly different from each other. In the case of freshwater tanks, the inhabitants are from the tropical areas. Obviously, they need the environment of tropical water bodies.
The environment of the tropical water bodies may change due to floods, drought, some chemical changes, and many more things. The inhabitants of these types of aquariums can survive without extensive care. The water of these tanks does not require much attention. Simple tank water can do the job.
You should check the pH level of the water before putting it in because different fish need different pH to thrive. You would also need a water heater and filter in your freshwater aquarium. You should change 10-15% of the water every two to four weeks.
Well, that sums it up for the freshwater aquarium.
It might be quite challenging and tricky to keep the optimal water conditions in a saltwater fish tank. You need to understand that the marine aquarium is a smaller model of the oceanic environment. The water condition there does not change rapidly. It remains almost the same for years.
The inhabitants are suited to the stable environment for ages. So, they cannot withstand the slightest changes in the water condition. They might need pampering. Therefore, the water condition here is to be modified and maintained with attention.
You will have to have the appropriate amount of marine salt. Yes, you heard it right. You will need ‘marine salt’ and not just any old table salt. Marine salt is an amalgamation of different minerals, including calcium, magnesium, potassium, even mercury, and arsenic! If you put table salt into your marine aquarium, your fish might say adios to you!
Freshwater aquariums are merciful in case the tank’s water is subtly changed. But with the marine aquarium, there is no chance for a change!
3) Equipment:
In terms of equipment, the freshwater tanks need much less equipment than their marine counterparts. Your freshwater aquarium can ideally thrive in smaller tanks. You should always put the substrate of your tank on the list first. The gravel is often aquarium sand or stones. Another thing you might consider putting in your freshwater aquarium is a variety of plants. You may put plants like Water Wisteria, Java Fern, Anubias, Cryptocoryne Beckettii, and so on.

You may also need a good filtration system when it comes to cleaning your tanks. The excessive wastes and debris are removed from the water by the filters, and thus, your tank water is purified.
The temperature of the water plays a crucial role when it comes to the health of your precious ones. You should also include an aquarium heater in your freshwater tank.
This is more or less all you need to set your freshwater aquarium.
Coming to the saltwater aquariums, you may need an extra powerful filtration system in your saltwater aquarium because purifying is the key to a well-maintained marine tank. You should keep the heater and thermometer to check the temperature of the tank regularly.
Marine aquariums often produce a greater amount of waste because of the live rock. Besides, the lighting (that too you need for your marine tank) often leads to algae accumulation in the tank. Consider putting protein skimmers to avoid the issue regarding waste and dirt.
Maintaining the pH level and salinity of water are the two most important things. You will also need powerheads, air pumps, and air stones for your saltwater fish tank.
Equipment for freshwater aquariums | Equipment for marine aquarium |
Tank Filter Heater pH test kit Substrate Plants | Tank(not less than 30 gallons) Filter (powerful one) Powerhead Air pump Airstone Protein skimmer Substrate Marine salt Lighting Thermometer Heater pH test kit Plants (scarce) |
4) Livestock:
The fish of the freshwater aquariums are easy to maintain. You may find them in every pet store out there. Let’s have a look at a list of the most popular freshwater fish.
You may include guppies, mollies, betta fish, goldfish, angelfish, golden dwarf barbs, and rainbowfish in your freshwater tank.
These fish do compromise with the changes in the tank water to an extent. They may withstand your faults due to inexperience.
You must have watched the Disney film “ Finding Nemo” based on the life of a clownfish. Aren’t they beautiful? Do you also want your own Nemo? Well, the good news is that clownfish are appropriate to include in your saltwater aquarium.
Generally, the saltwater tanks offer more vibrant and colorful livestock than freshwater aquariums. You may include flame angelfish, maroon clownfish, coral beauty, six-line wrasse, tomato clownfish, royal gramma basslet, and pajama cardinalfish in your saltwater aquarium.
We have mentioned earlier that saltwater fish can not tolerate the slightest changes in the water condition. They need pampering and attention to thrive. The feeding habits of saltwater fish are somehow different from freshwater fish. You should know the appetite of your marine buddies to provide them with a comfortable amount of food.
5) Cost:
The freshwater aquariums win in this category, undoubtedly.
Freshwater aquariums come on a pocket-friendly budget. The fish of the freshwater tanks are readily available in pet stores at a reasonable price. All the equipment is also comparatively less expensive.
On the other hand, you should consider spending half of your bank balance on saltwater aquariums. That was a good joke!
Marine aquariums can be a little heavy on your pocket. Saltwater fish are quite expensive as well as rare to find. You will also have to spend a lot of money on the equipment for the saltwater aquarium. Although, the vibrant fish and colorful corals of the marine aquarium (if kept with proper care) are worth every penny.
6) Number of fish in the tank:
The water of the freshwater aquariums tends to have more oxygen dissolved. Besides, there are plenty of plants in those aquariums providing more and more oxygen. Thus you may keep a considerable number of fish in your freshwater aquarium because your pets will not be uncomfortable at low levels of oxygen.
The water conditions of the marine or reef aquariums are starkly different from those of freshwater aquariums. The water holds almost 20% less oxygen in it. Besides, you cannot put an excessive number of living plants in the saltwater aquarium. Therefore, you should never keep your aquarium stuffed with fish. Otherwise, you may have to observe massive casualties.
Related:- Glass Vs Acrylic Aquarium: Who Gets The Winner’s Trophy?
At a glance:
Freshwater aquariums
- Flexible tank size
- Water condition requires moderate maintenance
- Readily available and less number of equipment
- Hardy fish, withstand subtle changes
- A considerable number of pets can be kept
- Pocket-friendly set up
- Cannot offer a vibrant scenario as the marine ones
- Algae accumulation
Saltwater aquariums
- Can include corals
- Absolutely beautiful
- Vibrant appearance
- Not applicable for tanks less than 30 gallons
- Need special equipment
- Cannot bear subtle changes of water condition
- Fewer numbers of fish to be kept
- Expensive
Five best fish tanks for you:
There is no such difference in reef aquariums and freshwater aquariums while speaking about the glass or acrylic made bowl or container itself. However, the setup is what differentiates them from each other.
Choosing tanks from a variety of products might be difficult. We have tried to ease your suffering regarding this issue. Check out our list of the five best aquariums.
1) Tetra Color Fusion Aquarium:

- Built with scratch-resistant glass
- Comes loaded with an LED hood
- Provides a natural daytime effect
2) Coralife LED Biocube Aquarium:

- Sleek modern hood with vibrant LED lighting
- 30 minutes sunrise/sunset function
- 60 minutes moonrise/moonset functions
- Compact and customizable built-in filtration
3) Marineland Contour Glass Aquarium Kit with Rail Light:

- Rounded corners
- Clear glass canopy
- Daylight and moonlight settings
4) GloFish Aquarium Kit Fish Tank :

- Low profile hood with LED energy-efficient lighting
- Comes with Tetra Whisper power filter with the cartridge, 50-watt aquarium heater, and thermometer
5) Hygger Horizon 8 Gallon LED Glass Aquarium:

- The unique convex arc curve shape
- Undetachable 3D background decor
- It comes with a super quiet power filter of 7W 110GPH
- Controllable DC12V/18W LED lights with extendable brackets
Our ratings:
Saltwater tank:
With their mesmerizing appearance, the saltwater tanks can remarkably intensify the grace and glamour of your room. Although they come with a detailed schedule of maintenance, you might consider keeping them. The colorful and interactive fish will surely steal your heart.
Considering all the factors mentioned above, we have decided to give it a 4.0/5.
Freshwater tank:
The freshwater tanks are also fascinating. A well-maintained freshwater tank with its green environment and colorful fish may impress you. Another advantage that you might find relaxing is that they come with a less detailed maintenance schedule. You need to indulge yourself in cleaning and taking care of both kinds of tanks. But the labor minimizes when it comes to the maintenance of the freshwater tanks.
Comparing all the pros and cons, we have decided to give it a round of applause with a score of 4.5/5.
General FAQs you should look at:
1) Is a saltwater tank harder to maintain than a freshwater tank?
Ans. The saltwater or marine tanks are miniature models of the oceanic underwater scenes. The oceanic ecosystem does not suffer from massive chemical or other water changes; besides, the water of these greater water bodies is starkly different from that of rivers and lakes. So you must give extra attention to the water condition (appropriate amount of marine salt), lighting, food habits, and other maintenance schedules that might be intricate. On the other hand, freshwater tanks do not include a much detailed schedule, although daily or periodic cleaning is necessary for you to keep the tank healthy.
2) Why is it bad to put saltwater fish in freshwater?
Ans. The saltwater fish will generally have saltwater inside its body. Now, if you put it in a freshwater tank or freshwater source, the water through osmosis will enter the fish’s body and swell its cells. Thus the fish will die. So, putting saltwater fish in freshwater is not a good idea.
3) Can you use a freshwater tank for saltwater?
Ans. The simple and straightforward answer to this question would be yes. Tanks or aquariums are specifically not designed for freshwater or saltwater. Therefore, you may use a freshwater tank for a saltwater setup and vice-versa. However, the setup must be changed in order to give your pets the optimal environment to live in.
4) How often do you have to change the water in a saltwater aquarium?
Ans. You should change the tank’s water every one or two weeks. Saltwater aquariums are supposed to be well-balanced in order to suit the oceanic environment. Therefore, performing 10- 20% water change every one or two weeks helps you maintain the water’s chemical balance and keep up your marine tank friends’ good health.
5) Can clownfish live in freshwater?
Ans. The straightforward answer would be NO! Clownfish is strictly supposed to live in saltwater. Their body structure and internal organs have been developed in a way to suit the saltwater environment. Therefore, you cannot put them in a freshwater tank. Otherwise, they will die. If you want your “Nemo,” you must keep a reef aquarium.
Editor’s choice:
After reading all the above-mentioned information, can we just say that you have already come to your decision? We presume you must have. But it is our duty to provide you with our ratings and choices. So, here we are.
Both saltwater and freshwater tanks can enhance the glamour and gorgeousness of your room. Undoubtedly, both are excellent in their appearance and beauty. But, considering all the pros and cons, our team has come to a decision here. We have observed that the freshwater aquarium is slightly better than the marine or reef aquarium. The maintenance and setup are not expensive and intricate. They are flexible and can withstand a subtly changed environment.
On the other hand, we have our beautiful reef aquariums, which are often the most desired ones for every aqua hobbyist. The marine aquariums are as pretty as their pictures. But the only drawback is that they are relatively costly and come with a detailed maintenance schedule. Also, they cannot bear the slightest changes in the environment.
So with a round of applause, we declare the winner of this battle as freshwater aquariums.
Conclusion:
Marine tanks and freshwater tanks both come with their specific maintenance. You must refrain from thinking that keeping a freshwater aquarium is an opportunity for you to be lazy! The simplest and shortest conclusion would be to TAKE CARE OF YOUR AQUARIUM PROPERLY. You must not be irregular in cleaning and changing water. Otherwise, you will end up having a murky aquarium with a handful of almost blind fish desperately trying to find food!
It doesn’t really matter what type of aquarium you are keeping. Your ultimate goal is to provide natural comfort to your lovely friends. It is a huge responsibility to keep an aquarium in your house. Taking good care and ensuring the health of your pets are the only keys to success here.
We hope we could help you to choose between the two aquariums with all the advantages and disadvantages mentioned earlier.
If you are determined enough to take on all the challenges and responsibilities, don’t sit and waste your time. Start preparing today and bring your aquarium home.
All the best!
Brian wasn’t just another Civil Engineer. His passion for Aquarium life was unknown to many until he decided to showcase it for the world. It seems like he made the right decision after all!