The Ultimate Guide to 5 Gallon Betta Fish Tanks (Setup & Care)

When it comes to fishkeeping in general and betta fish care in particular, the debate over tank size seems never-ending. Aquarium experts and betta enthusiasts have written a lot about the ideal and recommended tank size for betta fish. And obviously, with so many people come many opinions.

A newbie to the hobby is surely confused by so many tangles of the tank size. However, we’re not here to complicate things. Instead, we want to keep it simple for those new to betta keeping. We’ve also covered the topic of tank size for bettas in our comprehensive articles, which we encourage you to read before selecting a tank for your betta fish.

You may be thinking about getting a 5-gallon tank for your betta but not sure if it’s big enough? Maybe you’ve seen a lot of different opinions online and now you’re feeling unsure about what you actually need—like filters, heaters, and all the other gear.

In this article, we’re specifically focusing on our experience with 5-gallon betta tanks and all the important considerations that come with them like why it’s a perfect starting point for your betta?

We’ll provide recommendations for the best tanks and reviews from experts who have used these tanks. Additionally, we’ll cover accessories compatible with the 5-gallon tank, such as filters, air pumps, heaters, aquarium lights, and dividers.

Betta in a 5-Gallon Tank

The recommended tank size for a betta fish starts at 5 gallons. The best tank is the one that meets both the fish’s needs and the owner’s circumstances. A 5-gallon tank provides the perfect balance between fulfilling all the requirements of a betta fish and accommodating the owner. It’s a size that allows you to include almost all the essential accessories necessary for the better care of your betta fish.

A bigger tank is the first step towards providing a better life for your betta. While a larger tank is always the better option, a 5-gallon is the minimum recommended size when your constraints prevent you from getting a bigger one. A five-gallon tank adequately meets the needs and activities of a betta fish and allows you to maintain good control over the water parameters of the tank.

As long as the owner is doing their best to keep the fish happy, healthy, and enriched, the exact size of the tank is less important than the quality of care.

Why We Recommend a 5-Gallon Betta Fish Tank?

A lot of people wonder, “Is a 5-gallon tank enough for a betta?” Or they’ve heard bettas can live happily in small bowls. The truth? Those tiny bowls just don’t cut it.

Bettas need room to swim, explore, and feel secure. They also need clean, stable water, which is much harder to maintain in small betta tanks. Anything under 5 gallons makes it challenging to control water quality, temperature, and overall health.

Almost all aquarium experts agree over the fact that the smallest recommended size for a betta fish is 5-gallon. There are several reasons behind this claim which we discuss below.

Type of Betta Fish

The size of the tank you need often depends on the type of betta fish you have. Long-finned bettas, which are slow swimmers, often do well in a 5-gallon tank. On the other hand, bettas with shorter fins, such as plakats, are active swimmers and thrive in larger tanks than a 5-gallon. Similarly, shy bettas are mostly suited for 5-gallon tanks.

Water Stability

Stable water parameters like pH, temperature, and ammonia levels play a major role in the well-being of your betta fish. A 5-gallon tank reduces the risk of fluctuations in these parameters, which can otherwise stress the betta.

Easier Maintenance

Betta tanks require regular maintenance, such as cleaning and water changes. Smaller tanks accumulate waste faster, leading to poor water quality, while larger tanks dilute toxins more effectively. In a 5-gallon or larger tank, these maintenance tasks are performed quite efficiently.

Ample Space for Swimming

A 5-gallon US tank holds approximately 19 liters of water, which is enough space for a betta’s regular activities. It provides plenty of room for your betta to swim, explore, and exhibit natural behaviors.

Additionally, a 5-gallon tank works well with the filtration and heating systems and enhances the mental stimulation of your betta fish. In short, it provides the perfect balance for your betta’s well-being while being manageable for betta owners.

Tank Mates for 5-Gallon Betta Tank

While some betta owners like to add tank mates, it’s important to note that a 5-gallon tank is suitable only for a single betta. Tank mates are generally not recommended due to the betta’s aggressive behavior. However, if you want a livelier tank and are passionate about other bottom dwellers, amano shrimp, and mystery snails can adjust well in a 5-gallon betta tank.

Essential Equipment Checklist for a 5-Gallon Betta Tank

If you’re setting up a 5-gallon home for your betta fish, here’s a breakdown of what you’ll need, what each item does, and what to keep in mind—especially for a small tank like this one. We’ve also included rough price ranges and product tips to help you stay within budget.

Equipment	Purpose	Key Considerations
Heater	Maintains stable tropical temperature (78-80°F).	Must be submersible and correctly sized (e.g., 25W).
Thermometer	Monitors water temperature.	Adhesive strip, digital, or submersible glass type.
Filter	Removes waste and provides biological filtration.	Low flow is crucial (sponge filter or baffled HOB).
Substrate	Base layer for plants/decor; holds beneficial bacteria.	Fine gravel or sand (easy to clean, won’t snag fins).
Decor/Plants	Provides hiding spots, resting places, enrichment.	Smooth edges, live or silk plants preferred over plastic.
Water Conditioner	Removes chlorine/chloramine from tap water.	Essential for every water change.
Test Kit	Monitors ammonia, nitrite, nitrate, pH.	Liquid test kit recommended for accuracy (e.g., API Freshwater Master Kit).

5-Gallon Betta Tank Setup

One key factor when considering tank size is how the tank is set up. There should be enough decorations, ornaments, and live plants to create a natural-like habitat for betta fish. The setup for a 5-gallon betta fish tank and larger sizes is almost the same. The only difference lies in the size of the accessories, such as the filter, air pump, heater, lights, and dividers.

Though we have covered this topic in our separate article, of betta tank setup, here are the simple setup guidelines.

Choosing the Right Spot and Preparing the Basics

Setting up a 5-gallon betta tank starts with choosing the right location. Pick a flat, stable surface away from windows, heaters, and noisy areas to avoid stress and temperature swings. Once your tank is in place, it’s time to rinse the gravel or sand, decorations, and artificial plants using plain water—never soap. This helps remove dust and debris. After rinsing, spread the substrate evenly along the bottom of the tank to form the base layer.

Decorating and Filling the Tank

Next, arrange your plants and decorations to create plenty of hiding spots and resting areas. Bettas are ambush predators who love to sneak around and relax under cover. Once your decor is set, carefully add water. To avoid stirring up the substrate, pour the water slowly over a plate or plastic bag placed in the tank.

Making the Water Safe and Installing Equipment

Now it’s time to make the water safe for your betta. Add a water conditioner to remove harmful chemicals like chlorine and chloramine from tap water. Then, install your heater and filter. Position them properly, ensuring they’re both fully submerged if needed and functioning well.

Place a thermometer where you can easily read it, and set the heater to maintain a stable temperature between 78–80°F—ideal for a healthy, happy betta.

Understanding and Completing the Nitrogen Cycle

Before adding your fish, ensure the tank goes through the nitrogen cycle. This process allows good bacteria to grow, which helps break down toxic waste like ammonia and nitrite into safer nitrate. Cycling can take a few weeks, but it’s crucial to creating a stable environment.

Use a water test kit to monitor water quality, and once ammonia and nitrite levels read zero, and nitrates are under control, your tank is ready for its new finned friend!

Best 5-Gallon Betta Fish Tanks

Pros

1. Compact and Space-Saving: It is ideal for small spaces and still provides enough room for a single fish, such as a betta or goldfish.
2. Easy to Maintain: The tank is well suited for quick water changes and easy filter maintenance, requiring cleaning only 3-4 times a year.
3. Strong and Durable: It is made of strong, leak-proof acrylic material that offers a clear view.
4. Bright Lighting: The tank has a built-in light feature that enhances the visibility of your tank.
5. Quiet Filtration System: The tank has its own filtration system, which remains quiet during operation.

Cons

1. Acrylic is Prone to Scratches: The tank may require careful cleaning to avoid scratching and hazy surfaces.
2. Siphon System Flaw: Its built-in siphon may not work well, leading to water spillage. It is better to use a separate siphon.
3. Pumps Not Necessary for Bettas: Bettas can breathe from the surface, so a pump is optional.
4. Mineral Build-Up in Pump: The pump motor can freeze due to mineral deposits, requiring periodic cleaning.

Pros

1. Sturdy and Well-Designed: Strong, durable build with heavy glass and clean design, hiding equipment in the back sump area.
2. Good Water Circulation: The pump and return areas ensure efficient water circulation.
3. Roomy Sump: The sump area has plenty of space for additional equipment like heaters, CO2 diffusers, and bio media.
4. Minimizes Evaporation: The glass lid fits closely, preventing fish from jumping and reducing evaporation in warmer water of bettas.
5. Slideable Lid: Easy to slide back for feeding and maintenance without removing the entire lid.
6. Customizable Lighting: Suitable for stronger or upgraded lights, perfect for planted tanks.
7. Effective Filtration Options: It has a filtration with space for bio media and additional filter materials, ensuring crystal-clear water.
8. Adjustable Flow: Flow can be reduced by modifying the return tubing or adjusting the filter settings to suit a betta’s needs.
9. Long-Term Durability: The Tank holds up well over time, with no leaks or major issues after months or even a year of use.

Cons

1. Flimsy Black Plastic Cover: The back plastic cover is cheap and can be annoying when sliding it for feeding.
2. Clear Silicone on Back Panel: The clear silicone on the back divider panel stands out; black silicone would have been a better choice aesthetically.
3. Stock Lighting: The original light may need to be stronger for heavily planted tanks, requiring an upgrade.
4. Requires Simple Modifications: Some modifications, like adding a sponge to the filter or drilling holes in the return tubing, may be necessary to suit a betta’s needs.

Compatibility for Betta Fish

This tank is compatible with betta fish, especially for low-energy bettas like male long-finned bettas. With a few simple modifications, such as reducing the filter flow, adding resting places, and ensuring gentle water circulation, this tank provides a great environment for bettas. It’s also suitable for small tankmates like cherry shrimp or snails.

Pros

1.       Tank Design and Quality

• The tank is easy to set up, making it convenient for beginners to install.
• It is made of glass, providing a smooth and durable design.
• Its black sealant, instead of clear silicone, helps prevent the buildup of unwanted algae.

2.       Filter Features

• I appreciate its separate filter, which facilitates hobbyists with budget limitations. The filter is effective, adjustable, and generally quiet.
• It has an adjustable flow rate, which allows customization for different fish needs if you aim to keep the tank for your other pet in the future.
• It works well with minimal noise after a few simple adjustments, like using silicone pads.

3.       Accessories

• The good thing about the tank kit is that it comes with additional items like a net, water conditioner, and bio-enhancer.
• Its bright LED lights support plant growth and diffuse beautiful water reflections at night.

4.       User-Friendly

• The lid can be completely removed for easy cleaning.
• The packing also contains instructions that are helpful for those new to the hobby.
• The cord holes in the lid allow for easy heater installation.

Cons

1.       Filter Issues

• The manufacturer has fixed the filter position for easy installation for beginners, but it might reduce space for decorations.
• In some cases, the filters might buzz or rattle, which can be reduced with silicone pads but remains an inconvenience for sensitive users.

2.       Design Limitations

• The tank’s lid lacks a hinge, making it difficult to manage during cleanings.
• The filter and heater take up considerable space inside the tank, which leaves limited room for fish and plants.

Maintaining Your 5-Gallon Betta Tank for Long Term Health

To keep your betta healthy and your tank running smoothly, you’ll need to stick to a regular maintenance routine

Water Changes

In tanks like a 5-gallon, it’s very important to do small water changes often—about 20–25% once a week is perfect. This helps keep the water clean and safe without stressing your fish.

When doing a water change, remove the old water slowly and add fresh, treated water. Always test your tap water for chlorine or chloramine, and use a good water conditioner every time. It’s a must!

Test Water Parameters

Check your water regularly using a test kit. You’ll want to keep an eye on ammonia, nitrite, nitrate, and pH levels—these are key for your betta’s health. Test weekly if you’re new to it or at least every two weeks once things are stable.

Feed Your Betta

Feeding is another big part of care. Give your betta a high-quality pellet made just for bettas. Don’t overdo it—a small amount once or twice daily is enough. Too much food can dirty the water fast. You might be overfeeding if your fish is spitting food out or looks bloated. It might be underfed if your betta is not eating much and seems sluggish.

Read out more about betta fish food in our separate article.

Clean the Tank

Cleaning the tank is also part of the routine. Use a gravel vacuum to clean the bottom, gently wipe algae from the glass, and rinse your decorations when they look dirty.

You might also encounter minor issues like cloudy water or algae. These are common and usually easy to fix with better cleaning and water changes.

Always keep an eye on your betta’s behavior and appearance. A healthy betta is active, has bright colors, and eats well. It could be sick if it’s hiding a lot, has clamped fins, or isn’t eating.

Knowing your betta’s needs and staying on top of tank care will make your fish happy and healthy in its little underwater world.

Accessories (Divider, Heater, Filter, and Aquarium Lights)

5-Gallon Fish Tank Divider

As the name suggests, a fish tank divider is used to separate a single tank into different sections, providing the facility of keeping various fish in the same tank. Tank dividers are useful for multiple reasons, such as separating fish for breeding purposes, addressing health concerns, or keeping fish with different requirements in separate sections.

Since a 5-gallon tank is already small and the minimum recommended size, dividing it further reduces the available space for a betta fish. As mentioned earlier, we don’t recommend keeping tank mates in a 5-gallon betta fish tank. If you follow this advice, you likely won’t need to use a tank divider, as most of its problems are concerned with the tank mates.

However, we can’t deny the fact that you may need a tank divider for shorter periods. Its temporary usage may be necessary in situations like when you need to quarantine your betta due to injury or illness and can’t afford a smaller hospital tank. If that’s the case, you can purchase our top-rated tank dividers.

ONE Set Clear Fish Tank Divider Board

The Spritool tank transparent tank divider (view it on Amazon), designed with a removable white protective film, can be bent, cut, and assembled to fit any tank size. We use the same divider for our most betta tanks because it allows you to easily partition your aquarium without compromising its aesthetics. It is made of high-quality materials which ensures the safety of your fish.

The divider is perfect for increasing the survival rate of baby fish, isolating aggressive or diseased betta fish, and maintaining a healthy environment.

This divider could work well if you prioritize sturdiness and secure separation for your fish. However, if you’re looking for a clear visual interaction or aesthetics divider, this product may disappoint due to its tendency to lose transparency.

5-Gallon Fish Tank Filter

Filters play an essential role in maintaining stable water parameters, keeping water clean, and reducing harmful substances from the tank. The three widely used filters for a betta fish are an Internal Filter, an HOB (Hang-on-back) filter, and a Sponge filter.

Betta fish are shallow water creatures that prefer gentle filtration and minimal water flow, which can be ensured using the sponge filters. These filters are inexpensive and quite effective in their operations for small tanks from 2.5-gallon to 5-gallon tanks. However, sponge filters require an air pump, which can create some noise.

The Pawfly Three-pack Sponge Filter (check it on Amazon) is installed in one of our 5-gallon betta tanks, which is quite effective in its operation. This filter works best for tanks of size 5-10 gallons due to its quiet aeration and easy-to-clean features.

If you prioritize noise reduction and compactness, a Tetra Internal Filter (check it on Amazon) seems best that comes with an air pump, helping to oxygenate the water.

For ease of use and better customization of filtration, an HOB filter is ideal for a 5-gallon betta tank. The NICREW Slim HOB Filter (check it on Amazon) is a top recommended by most aquarists because of its quality filtration and easy assembly.

Find out more regarding betta tank filters in our in-depth article.

Best Heaters for a 5-Gallon Tank

Bettas and other species of the gourami family thrive in temperatures warmer than room temperature, so they need a separate heater installed in their tanks. When choosing a heater for betta tank, you should consider the power of the device, its adjustability, and the preset reading.

We use the Hygger Glass Aquarium Heater (check it on Amazon) for our 5-gallon betta tank because of its compact design and good temperature regulation. The device has powerful performance and a red indicator light feature, which allows you to monitor your device and the tank temperature effectively.

Another good option for your 5-gallon tank is the Aqueon Adjustable Pro Aquarium Heater (check it on Amazon), which is recommended for maintaining a constant water temperature. This feature matches with the betta’s need for consistent water temperature. However, you may need to pair it with a separate thermometer to ensure temperature accuracy.

Best Aquarium Lights for a 5-Gallon Tank

Lighting is very critical in setting up a planted tank. It ensures proper plant growth and maintains a healthy environment for your fish.

For your 5-gallon planted betta tank, the Nicrew Classic Plus (check it on Amazon) would be the best option. Its dimmable settings offer great flexibility, allowing you to customize the light output based on your plants’ needs. If you decide to grow more demanding plants in the future, you can adjust the light intensity without buying a new light. Additionally, it’s an affordable, well-reviewed option by many aquarists for small tanks.

If you are interested in a tank light operating under pre-programmable cycles with different phases during the 24/7 life cycle, then Hygger Advanced Aquarium Light (check it on Amazon) is the best option for a 5-gallon tank.

Find out more on betta fish lighting in our comprehensive article.

Should You Upgrade to a 10-Gallon?

In conclusion, whether or not you should upgrade from a 5-gallon to a 10-gallon tank depends on several factors:

• Space and Budget: If you have the space and budget for a 10-gallon betta tank, it can offer your betta more room to swim and improve water quality.
• Betta’s Personality: For active bettas, a 10-gallon might be more suitable, while long-finned bettas might be just as happy in a 5-gallon.
• Maintenance: Larger tanks can be easier to maintain in terms of water quality, but they also require more effort in terms of cleaning and plant maintenance.

At the end of the day, if your betta seems happy, is active, eating well, and displaying vibrant colors, your 5-gallon setup might be perfectly fine. However, if you want to give your betta more room to explore, a 10-gallon upgrade is a great option. Ultimately, the most important factor is providing the best care within the limitations of your living environment.