10 Best Types Of Fish For 20-gallon Tanks [2025]
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Choosing the best types of fish for 20-gallon tanks can be a daunting task, especially with so many options available and varying care requirements. To simplify your search, we meticulously shortlisted ten ideal fish species that thrive in this size tank, taking into account compatibility, ease of care, and aesthetic appeal. Our curated list is designed to save you time and hassle, ensuring you find the perfect aquatic companions for your home aquarium without the overwhelming research process.
Top 10 Types Of Fish For 20-gallon Tanks In The Market
Types Of Fish For 20-gallon Tanks Review
- Tetra Glass Aquariums are made in the USA and are built to last with scratch resistant glass
- The Tetra Aquarium comes loaded with an LED hood, that provides a natural daytime effect and a Whisper Filter that is whisper quiet while providing powerful, dependable water flow
- Artificial Plants add a unique, natural ocean feel while giving your fish a place to hide which reduces fish stress
- The Tetra Kit includes: one 20 Gallon Glass Aquarium, one LED hood, one Tetra Mini UL Heater, one Tetra Whisper 20 Filter, one artificial Boxwood Plant Mat, four artificial plants. Add gravel and fish to complete your aquarium
- Aquarium Dimensions: 24.2" L x 12.4" W x 16.7" H
- CLEAR GLASS AQUARIUM: Enjoy the clearest view of your fish while creating a natural healthy environment with Lifegard Clear Glass Aquarium.
- QUALITY CRAFTMANSHIP: Lifegard Clear Glass Aquarium feature an Ultra Clear glue joint using German engineered glue for highest quality, an Insulation pad for tank base protection.
- DIMENSIONS: Length: 24.40" Width: 12.20" Height: 15.74" Glass thickness: 6mm Volume: 20 gallons
- AQUARIUM INCLUDES: A high clarity transparent extra clear glass and a black dense foam leveling mat
- LIFEGARD Brand is YOUR GO-TO RESOURCE FOR AQUARIUM, POND & AQUACULTURE PRODUCTS: Lifegard Aquatics features an extensive line of high-quality aquaculture products that include fountains, pumps, bulkhead fittings and commercial aquatic and pond equipment. From crystal aquariums to full spectrum LED lighting, trust in Lifegard for all of your aquatic needs.
- 100% HIGH-TRANSPARENT GLASS MATERIAL - The fish tank is indeed made of glass after a 3-meter drop and shatter test. If you think it's not, you can try to break it and we'll replace it for free.
- WATER TEMPERATURE DETECTION SYSTEM - The fish tank comes with a water temperature detection system, which can help you detect the water temperature and ensure a good living environment for the fish.
- PLANT LIGHTS - 3 types of LED lights provide photosynthesis for plants, providing more oxygen for your aquarium. Reduce adverse reactions of fish caused by lack of oxygen.
- FISH FAVORITE - You can keep bettas, tropical fish, reef fish, guppies, shrimps, crabs, betas and snails in this 20-gallon box, or use it as a fish breeding box.
- FISH FAVORITE - You can keep fighting fish, tropical fish, reef fish, turtles, peacock fish, shrimp, crabs, fighting fish, and snails in this 20-gallon box, or use it as a box for fish.
- Only Compatible with Aqueon 20 Gallon LONG tanks ONLY. Tank size 30.25” x 12.5”x12.75” This divider WILL NOT fit 20 Gallon Tall tanks.
- Easy to install and maintain - No Suction Cups Required
- Made from a closed cell pvc, it’s solid, study and none toxic.
- Adjustable sidebars for the perfect fit. Slide sidebars out to touch the glass. Slide sidebars up to fit securely under the rim.
- Suitable for reptile tanks when siliconed in place.
- ALL THE EQUIPMENT NEEDED to get started in one box
- LOW PROFILE HOOD contains vibrant cool white LED lighting to bring your aquatic environment to life
- SMARTCLEAN INTERNAL POWER FILTER, providing quick and easy water changes to help improve water quality.
- PRESET HEATER will keep your aquarium temperature at a constant 78 degrees, appropriate for most tropical fish
- KIT INCLUDES: glass aquarium, low profile LED hood, SmartClean internal power filter size medium, EcoRenew filter cartridge size medium, submersible preset heater 50W, premium fish food sample, water conditioner sample, fish net, thermometer and setup guide
- SilentTriple Filtration Pro: A 3-in-1 whisper-quiet pump combines oxygenation, water circulation, and filtration. Self-cleaning design reduces 70% maintenance while creating a mesmerizing waterfall effect.
- Crystal-Clear Premium Glass & 3-Color LED: Crafted with 5mm ultra-HD glass for razor-sharp underwater views. Reinforced with a 3-meter drop-tested anti-burst design, paired with customizable 3-color LED lighting to showcase aquatic life vibrantly, day or night.
- Smart TempGuard Monitoring: An integrated real-time water temperature sensor automatically tracks fluctuations, ideal for delicate species like shrimp or tropical fish.
- Gift-Ready Hassle-Free Setup: Flip-top design, easy to assemble and maintain, easy to change water or feeding, suitable as a gift for family or friends.
- After-Sales Service: Your satisfaction is our priority. Should you receive defective items or encounter missing parts, contact us immediately.
- Power Supply and LED Light: The aquarium stand includes a power strip with 2 AC outlets and 2 USB ports to power your aquarium circulator, oxygen pump and more. Featuring multiple colors and modes, the LED light strip creates a visually appealing ambience
- Spacious Storage: This fish tank stand measures 27.6"L x 15.7"W x 32.3"H with a wide tabletop that holds a fish tank with 20-gallon capacity, while the bottom shelf can be used as a 5-10 gallon small fish tank stand, turtle tank stand or reptile terrarium stand. The middle cabinet neatly organizes fish food, nets and other accessories
- Stable and High Load-bearing Capacity: Made of quality particleboard and metal frames, this 20 gallon fish tank stand incorporates X-braces for sturdiness and adjustable feet for balance. The dependable and stable stand can support up to 300 lb at the top and 110 lb at the bottom
- Simple and Versatile: With a classic and concise color scheme and exterior design, this tank stand exudes a rustic farmhouse flair. Ideal for use as a aquarium stand, or to place plants, decorations, etc., the multifunctional fish tank stand seamlessly integrates into your home space
- Complete Accessories: Each part of the fish tank stand is labeled with a serial number, along with all the necessary tools and a detailed illustrated manual. Please refer to the step-by-step installation instructions to assemble your own fish tank stand
Our Review Process
To ensure you get reliable product recommendations, we follow a detailed review methodology that includes:
- Market Research: Scanning best-selling and trending products in this category.
- User Feedback: Reviewing customer reviews, star ratings, and complaints.
- Hands-On Testing: Trying select products ourselves when feasible.
- Feature Comparison: Evaluating specs, durability, pricing, and safety.
- Expert Opinions: Consulting with niche experts or credible reviewers.
We independently select the top 10 options based on value, quality, and usability. To learn more, visit our detailed review process.
Key Considerations Before Buying Fish for a 20-Gallon Tank
1. Tank Size and Fish Size
When setting up a 20-gallon tank, it’s essential to choose fish that can comfortably thrive in the available space. Larger fish require more room to swim and grow, while smaller species may feel cramped in a smaller environment. Ensure that the adult size of the fish you choose is compatible with the tank’s dimensions.
2. Compatibility of Fish Species
Not all fish species get along well together. Before purchasing, research the temperament and social behavior of potential fish. Some species are territorial or aggressive, while others are peaceful. Mixing incompatible fish can lead to stress, aggression, and even fatalities in the tank.
3. Water Conditions
Different fish have varying requirements for water parameters such as pH, temperature, and hardness. It’s crucial to select fish that can thrive under the same water conditions. Perform regular tests for these factors and choose species that have similar needs to maintain a stable environment.
4. Filtration and Maintenance
A 20-gallon tank requires adequate filtration to maintain water quality. Some fish produce more waste than others, which can affect the tank’s cleanliness. Consider how often you are willing to perform maintenance and choose fish accordingly. Low-maintenance species might be more suitable if you have a busy lifestyle.
5. Stocking Levels
Overstocking a tank can lead to poor water quality and stressed fish. As a general rule, aim for one inch of fish per gallon of water, though this can vary based on the species and tank setup. Plan your stocking levels carefully to ensure a healthy and balanced aquarium.
6. Aquascaping and Environment
The layout of your tank—including plants, rocks, and hiding spots—can influence the fish you choose. Some species prefer dense vegetation or caves for hiding, while others thrive in open swimming spaces. Consider how the tank’s design will support the needs and behaviors of your fish.
7. Feeding Habits
Fish species have different dietary requirements. Some are herbivores, while others are carnivores or omnivores. Ensure you can provide appropriate food for the species you select. Additionally, consider the feeding frequency and types of food available for your chosen fish.
8. Lifespan and Commitment
Fish can have varied lifespans, ranging from a few years to several decades. Be prepared for the long-term commitment of caring for your fish and providing a stable environment throughout their lives. Research the expected lifespan of the species you are considering to ensure you are ready for the journey.
FAQs
What types of fish are suitable for a 20-gallon tank?
Some suitable fish for a 20-gallon tank include small species such as guppies, neon tetras, bettas, and platies. You can also consider dwarf cichlids like Apistogramma or smaller catfish like Corydoras. It’s important to research compatibility and choose fish that will thrive in a community setting.
Can I keep a betta fish in a 20-gallon tank?
Yes, a betta fish can thrive in a 20-gallon tank. In fact, a larger tank is beneficial as it provides more space for swimming and helps maintain stable water conditions. Just be cautious about tank mates, as bettas can be aggressive towards other fish with long fins or similar colors.
How many fish can I put in a 20-gallon tank?
A general guideline is to allow one inch of fish per gallon of water, but this can vary based on the species and their behavior. For a 20-gallon tank, you could typically house around 10-15 small fish, depending on their adult size and compatibility. Always monitor water quality and fish health to avoid overcrowding.
Are there any fish that should not be kept in a 20-gallon tank?
Yes, larger fish such as goldfish, oscars, or larger cichlids are not suitable for a 20-gallon tank due to their size and space requirements. Additionally, fast-swimming species or those that require more swimming space may also not thrive in a smaller tank.
What are some peaceful community fish for a 20-gallon tank?
Peaceful community fish that do well in a 20-gallon tank include guppies, neon tetras, danios, and harlequin rasboras. These species are generally non-aggressive and can coexist with other small fish, making them ideal for community setups.
Can I mix freshwater and saltwater fish in a 20-gallon tank?
No, freshwater and saltwater fish cannot be mixed in the same tank. They have different water chemistry requirements and would not survive in an incompatible environment. It’s essential to choose either a freshwater or saltwater setup for your 20-gallon tank.
What plants are suitable for a 20-gallon fish tank?
Plants such as Java fern, Anubias, and Amazon swords are great choices for a 20-gallon tank. They provide hiding spaces for fish, help improve water quality, and enhance the overall aesthetics of the aquarium. Make sure to choose plants compatible with your fish species and lighting conditions.
How often should I change the water in a 20-gallon tank?
It’s recommended to change 10-15% of the water weekly or 20-25% bi-weekly in a 20-gallon tank. Regular water changes help maintain water quality by removing toxins and replenishing minerals. Always check the water parameters before and after changes.
The Bottom Line
In conclusion, selecting the right fish for a 20-gallon tank is essential for creating a vibrant and harmonious aquatic environment. The ten species highlighted in this article have been carefully chosen based on factors such as compatibility, size, temperament, and care requirements. Each of these fish not only complements the limited space of a 20-gallon aquarium but also brings a unique beauty and personality that can enhance your aquatic display. By understanding the specific needs and behaviors of these fish, hobbyists can build a thriving community tank that is both visually appealing and ecologically balanced.
By following our curated list of the best types of fish for 20-gallon tanks, you can ensure that you make informed decisions that promote the well-being of your aquatic inhabitants. Whether you are a seasoned aquarist or a beginner just starting out, adhering to these recommendations will help you avoid common pitfalls, such as overstocking or incompatibility issues. With the right choices, your 20-gallon tank can become a beautiful sanctuary that brings joy to both you and your fish for years to come.
