Top 10 Freshwater Fish for a 30 Gallon Aquarium (2025)
Published: 29 Apr 2025
Finding the right freshwater fish for a 30 gallon aquarium can be a challenge. Stocking too many fish or choosing incompatible species can lead to overcrowding, stress, and poor water quality. This can result in unhappy, unhealthy fish. For 2025, aquarium trends are moving toward balanced ecosystems, sustainable fish choices, and greater species diversity within appropriately sized environments.
Whether setting up a new tank or restocking an existing 30-gallon aquarium, this guide will help you select the best fish for your aquatic community. Each recommendation considers bioload, compatibility, sustainability, and visual appeal to create a vibrant, healthy underwater environment.
Understanding Your 30-Gallon Ecosystem
Before selecting fish, it’s essential to understand what makes a 30-gallon tank unique:
- Moderate bioload capacity: Can support multiple small to medium-sized species
- Versatile dimensions: Typically 36″L × 12″ W × 16″H, providing good swimming length
- Stable parameters: Larger than nano tanks, allowing for more stable water chemistry
- Stocking limit: Generally safe for 15-20 small fish, depending on species and filtration
Top 10 Freshwater Fish for a 30 Gallon Aquarium
1. Dwarf Gourami (Trichogaster lalius)
| Size | 2-3 inches (5-7.5 cm) |
| Care Level | Intermediate |
| Temperament | Peaceful to semi-aggressive |
| Minimum Number | 1 (male) or one male with 2-3 females |
Water Parameters
- Temperature: 72-82°F (22-28°C)
- pH: 6.0-7.5
- Hardness: Soft to medium
Why They’re Trending for 2025
Dwarf Gouramis have significantly improved breeding practices, with more vibrant and healthy specimens becoming available. The “Flame” and “Neon Blue” varieties are particularly popular for 2025, offering stunning centrepiece options for moderately sized tanks. New developments in disease resistance have also made these fish more robust than earlier generations.
Care Tips
Provide plenty of floating plants as they’re labyrinth breathers that occasionally need access to the surface. Males can be territorial with each other, so keep only one male per tank. A well-planted aquarium with hiding places helps reduce stress and showcases its vibrant colours.
Compatibility: It works well with peaceful community fish like tetras, rasboras, and corydoras. Avoid fin-nipping species or very active swimmers that might stress it.
Sustainability Note: Look for tank-bred specimens from reputable sources, as these are more likely to be healthy and ethically sourced.
2. Honey Gourami (Trichogaster chuna)
| Size | 2 inches (5 cm) |
| Care Level | Easy to Intermediate |
| Temperament | Peaceful |
| Minimum Number | 1 or small groups |
Water Parameters
- Temperature: 72-82°F (22-28°C)
- pH: 6.0-7.5
- Hardness: Soft to medium
Why They’re Trending for 2025
Honey Gouramis are gaining popularity as a more peaceful alternative to Dwarf Gouramis. When in breeding condition, males display a stunning honey-gold colouration. Their smaller size and gentler temperament make them ideal for community tanks. For 2025, the “Red Honey” variety is particularly sought after for its vibrant appearance.
Care Tips
Like all gouramis, they appreciate floating plants and access to the surface for air. They’re less disease-prone than Dwarf Gouramis but still benefit from stable water conditions and a varied diet.
Compatibility: One of the most peaceful gourami species, they mix well with nearly all non-aggressive community fish.
Sustainability Note: They are almost exclusively tank-bred, making them a sustainable choice for aquarium keepers.
3. Kuhli Loach (Pangio kuhlii)
| Size | 3-4 inches (7.5-10 cm) |
| Care Level | Easy to Intermediate |
| Temperament | Peaceful, shy |
| Minimum Number | 6+ |
Water Parameters
- Temperature: 73-86°F (23-30°C)
- pH: 5.5-7.0
- Hardness: Soft to medium
Why They’re Trending for 2025
These eel-like bottom dwellers have become popular as aquarists seek interesting behaviours and unique appearances. Their nocturnal activity patterns and social interactions make them fascinating, especially in the evening hours with subdued lighting. Advanced breeding techniques have made them more readily available than in previous years.
Care Tips
Provide a fine sand substrate to protect their sensitive barbels and allow natural sifting behaviour. Include plenty of hiding places like caves, driftwood, and dense planting. They’re more active and visible when kept in larger groups.
Compatibility: They are excellent with peaceful community fish. Their bottom-dwelling nature means they occupy a different tank zone than many popular species.
Sustainability Note: While historically wild-caught, captive breeding programs are increasingly successful, making sustainably sourced specimens more available.
4. Cherry Barb (Puntius titteya)
| Size | 2 inches (5 cm) |
| Care Level | Easy |
| Temperament | Peaceful |
| Minimum Number | 6-8 |
Water Parameters:
- Temperature: 73-81°F (23-27°C)
- pH: 6.0-7.5
- Hardness: Soft to medium
Why They’re Trending for 2025
Cherry Barbs offer vibrant colouration without the aggression issues of some other barb species. Males display a brilliant cherry-red colour, making them stand out in planted aquariums. Their peaceful nature and hardiness make them perfect for community tanks, and selective breeding has produced more intensely coloured varieties for 2025.
Care Tips
Provide plants and hiding spaces to help them feel secure. Males display their best colouration when kept with females in a ratio of 1-2 males to 3-4 females.
Compatibility: Works well with most community fish of similar size, including tetras, rasboras, gouramis, and bottom dwellers.
Sustainability Note: Almost exclusively captive-bred, making them an environmentally responsible choice.
5. Bolivian Ram (Mikrogeophagus altispinosus)
| Size | 3 inches (7.5 cm) |
| Care Level | Intermediate |
| Temperament | Peaceful |
| Minimum Number | Pair or small group |
Water Parameters
- Temperature: 73-79°F (23-26°C)
- pH: 6.0-7.5
- Hardness: Soft to medium
Why They’re Trending for 2025
Bolivian Rams offer cichlids’ fascinating behaviour and intelligence without aggression or large size requirements. Their subtle elegance and amber-gold bodies accented by red fins and distinctive facial markings make them ideal centrepiece fish. For 2025, enhanced breeding techniques have produced specimens with more vivid colouration and finnage.
Care Tips
Provide a sandy substrate for natural sifting behaviour and arrange rocks and driftwood to create territories and sight breaks. They appreciate a mix of open swimming areas and densely planted zones.
Compatibility: One of the most peaceful cichlids, they work well in community tanks with similarly sized, non-aggressive species.
Sustainability Note: Primarily tank-bred now, reducing pressure on wild populations.
6. Corydoras Catfish (Various species)
| Size | 2-3 inches (5-7.5 cm), depending on species |
| Care Level | Easy |
| Temperament | Peaceful |
| Minimum Number | 6+ |
Water Parameters
- Temperature: 72-80°F (22-27°C)
- pH: 6.0-7.8
- Hardness: Soft to medium
Why They’re Trending for 2025
Corydoras catfish remain hobby staples for their charming personalities and practical cleaning habits. For 2025, less common species like Corydoras sterbai (Sterba’s Cory) and Corydoras panda (Panda Cory) are particularly popular due to their distinctive patterns. Their social behaviour and comical antics make them engaging additions to any community tank.
Care Tips
Provide a fine sand substrate to protect their sensitive barbels. They appreciate caves and driftwood for shelter and will be more active and visible when kept in larger groups of 6 or more of the same species.
Compatibility: Extremely peaceful and works well with almost any non-aggressive community fish.
Sustainability Note: Most common species are tank-bred, though some rarer varieties may still be wild-caught. Research the specific species before purchasing.
7. Celestial Pearl Danio (Danio margaritatus)
| Size | 1 inch (2.5 cm) |
| Care Level | Intermediate |
| Temperament | Peaceful |
| Minimum Number | 8-10 |
Water Parameters:
- Temperature: 68-75°F (20-24°C)
- pH: 6.5-7.5
- Hardness: Soft to medium
Why They’re Trending for 2025
These micro-fish have earned their “celestial” name with star-like white spots against a deep blue body, complemented by vibrant red-orange fins. Their tiny size allows for larger schools, even in a 30-gallon tank, creating mesmerizing displays of movement and colour. Improved breeding techniques have make them more accessible and affordable by 2025.
Care Tips
Provide dense planting, especially along the edges of the tank, with open swimming areas in the middle. They appreciate slightly cooler water than many tropical fish and do best in well-established aquariums.
Compatibility: It works well with peaceful small fish, such as small tetras, rasboras, and peaceful bottom dwellers.
Sustainability Note: Originally threatened by overharvesting, they’re now widely available as captive-bred, making them an ethical choice for conscientious aquarists.
8. Apistogramma Species (Apistogramma cacatuoides, A. borellii, etc.)
| Size | 2-3 inches (5-7.5 cm) |
| Care Level | Intermediate to Advanced |
| Temperament | Peaceful to semi-aggressive |
| Minimum Number | Pair or trio (1 male, two females) |
Water Parameters:
- Temperature: 74-82°F (23-28°C)
- pH: 5.5-7.0 (species dependent)
- Hardness: Soft
Why They’re Trending for 2025
Apistogramma dwarf cichlids are experiencing a surge in popularity as aquarists seek intelligent, interactive fish with minimal space requirements. Their vibrant colours, fascinating breeding behaviour, and personality make them the perfect centrepiece fish. For 2025, varieties like the “Triple Red” Cockatoo Cichlid (A. cacatuoides) and “Blue Steel” (A. borellii) are particularly sought after.
Care Tips
Provide territories with caves, coconut shells, or ceramic shelters. A fine sand substrate, including leaf litter, creates natural conditions and slight water acidification. Males can be territorial during breeding, so design the tank with sight breaks and multiple territories.
Compatibility: Best with peaceful community fish that prefer the middle and upper water column. Avoid fin-nippers or very active species that might stress them.
Sustainability Note: While some are wild-caught, captive breeding programs have been successful with many species. Research the specific variety and source before purchasing.
9. Harlequin Rasbora (Trigonostigma heteromorpha)
| Size | 1.5-2 inches (3.8-5 cm) |
| Care Level | Easy |
| Temperament | Peaceful |
| Minimum Number | 8-10 |
Water Parameters:
- Temperature: 73-80°F (23-27°C)
- pH: 6.0-7.5
- Hardness: Soft to medium
Why They’re Trending for 2025
Harlequin Rasboras combine an elegant appearance with a hardy constitution, making them perfect for beginners and experienced aquarists. Their distinctive triangular black marking against a copper-orange body creates a striking pattern, primarily when they school together. Their popularity continues to grow for 2025 as aquarists appreciate their reliability and visual impact.
Care Tips
Provide open swimming areas with planted sections for security. They display their best colouration in slightly acidic water with tannins from botanicals or driftwood.
Compatibility: Excellent community fish that work well with virtually all peaceful species of appropriate size.
Sustainability Note: Almost exclusively captive-bred now, making them a sustainable choice.
10. Bristlenose Pleco (Ancistrus spp.)
| Size | 4-5 inches (10-12.5 cm) |
| Care Level | Easy |
| Temperament | Peaceful |
| Minimum Number | 1 |
Water Parameters:
- Temperature: 73-82°F (23-28°C)
- pH: 6.0-7.5
- Hardness: Soft to medium
Why They’re Trending for 2025
Unlike common plecos that quickly outgrow most home aquariums, Bristlenose Plecos remain manageably sized while offering excellent algae-eating capabilities. For 2025, colour variants like albino, super red, and longfin varieties have become particularly desirable. Their distinctive “bristles” on males add character and visual interest to the practical benefits they bring.
Care Tips
Provide driftwood, which they require for proper digestion. While they consume algae, they supplement with sinking algae wafers, blanched vegetables, and occasional protein-rich foods. Include caves or shelters for hiding and breeding.
Compatibility: Very peaceful and compatible with most community fish. Multiple males may become territorial with each other.
Sustainability Note: They are widely available as captive-bred, making them both sustainable and adaptable to aquarium life.
Creating the Ideal 30-gallon Setup
To get the most from your stocking choices, consider these setup recommendations:
Filtration
A tank of this size requires adequate filtration to handle the bioload. Options include:
- Hang-on-Back Filter: Aim for models rated for at least 60 gallons for better turnover
- Canister Filter: Provides excellent mechanical, biological, and chemical filtration
- Sponge Filter: Great as a secondary filter for additional biological filtration
Planting Strategies
Live plants improve water quality, provide hiding places, and create a more natural environment:
- Easy Beginner Plants: Anubias, Java Fern, Amazon Sword, Vallisneria
- Floating Plants: Water Lettuce, Frogbit, Salvinia (especially beneficial for gouramis)
- Fast-Growing Plants: Hornwort, Water Wisteria (help with nutrient control)
Aquascaping for Fish Behavior
Design your aquascape with your fish species in mind:
- Open Swimming Areas: Essential for schooling species like rasboras and tetras
- Cave Structures: Important for bottom-dwellers and territorial species like Apistogramma
- Planted Borders: Provide security while maintaining a central swimming space
- Different Height Elements: Use tall background plants, mid-ground features, and foreground carpeting to utilize the entire tank volume
Stocking Strategies for 30-Gallon Tanks
A well-balanced 30-gallon community might include:
Example Community 1: Colorful Peaceful Community
- 1 Honey Gourami (centrepiece)
- 10 Harlequin Rasboras (upper/middle)
- 8 Celestial Pearl Danios (middle)
- 6 Corydoras (bottom)
- 1 Bristlenose Pleco (algae control)
Example Community 2: Cichlid Showcase
- Pair of Bolivian Rams or Apistogramma (centrepiece)
- 8 Cherry Barbs (middle)
- 6 Kuhli Loaches (bottom)
- 1 Bristlenose Pleco (algae control)
Example Community 3: Nano Fish Collection
- 12 Celestial Pearl Danios (middle)
- 10 Ember Tetras (upper/middle)
- 6 Pygmy Corydoras (bottom)
- 5 Kuhli Loaches (bottom)
Sustainable and Ethical Fishkeeping for 2025
As we move through 2025, the aquarium hobby continues to emphasize sustainable practices:
- Choose captive-bred fish whenever possible to reduce pressure on wild populations
- Research species origin and purchase from retailers who can verify their sources
- Support local fish stores that demonstrate ethical sourcing and proper fish care
- Consider species’ natural behaviours and provide environments where they can thrive
- Start with a fully cycled tank and introduce fish gradually to ensure water quality stability
Maintenance Tips for a Thriving 30-Gallon Aquarium
Maintaining a healthy environment ensures your fish display their best colours and behaviours:
- Weekly water changes of 25-30% to maintain water quality
- Regular testing for ammonia, nitrite, nitrate, and pH
- Gravel/substrate vacuuming during water changes to remove organic waste
- Filter maintenance according to manufacturer recommendations (without disrupting beneficial bacteria)
- Careful feeding to avoid excess waste – most fish benefit from small, frequent feedings rather than one large daily feeding
Conclusion
A 30-gallon tank provides an ideal setting for a vibrant, balanced community of freshwater fish. By choosing species that align in size, temperament, and habitat needs, you can create a thriving, sustainable ecosystem. In 2025, the best freshwater fish for a 30 gallon aquarium includes everything from the peaceful Harlequin Rasboras to the charming Bolivian Rams and the unique Kuhli Loaches.
Successful fishkeeping hinges on balancing fish compatibility, tank size, and care routine. With the right selections and proper maintenance, your 30-gallon aquarium will flourish, offering years of enjoyment and a window into the fascinating underwater world.
The number of fish you can keep in a 30-gallon tank depends on the species and their space needs. A general rule of thumb is 1 inch of fish per gallon, which can vary. Smaller species like neon tetras or guppies need less space than larger fish like angelfish or gouramis. Always consider the adult size of each fish and avoid overcrowding to maintain water quality and fish health.
For a 30-gallon tank, it is essential to avoid fish that grow too large or require more space. Fish like Oscar cichlids or large goldfish species, which can grow over 12 inches, are unsuitable. Additionally, avoid overly aggressive species that may not get along with smaller, peaceful fish. Choosing species known for their calm temperament and compatible size is best.
Yes, live plants are a great addition to a 30-gallon aquarium. They help maintain water quality by absorbing nitrates and providing oxygen, offering hiding spots and natural decoration for fish. Choose low-maintenance plants like Java fern, Anubias, and Cryptocoryne, which thrive in various conditions. Be mindful of your fish’s needs; some may nibble on specific plant species.
Routine maintenance is key to keeping a 30-gallon tank healthy. Aim for 20-30% partial water changes every 1-2 weeks, depending on your fish load and water quality. Also, clean the tank substrate with a gravel vacuum during water changes to remove debris. Filter maintenance is crucial, too, so clean the filter every month or so, but avoid over-cleaning, as beneficial bacteria need time to thrive.
Introducing new fish gradually is essential to prevent stress and aggression. Begin by acclimating new fish to the tank’s water conditions by floating the bag in the aquarium and slowly adding water over 30 minutes. After acclimation, gently release the fish into the tank. Ensure the existing fish are not territorial or aggressive to newcomers. Introducing only a few fish at a time will help maintain stability in the tank.
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- Be Respectful
- Stay Relevant
- Stay Positive
- True Feedback
- Encourage Discussion
- Avoid Spamming
- No Fake News
- Don't Copy-Paste
- No Personal Attacks
