How Many Guppies and Neon Tetras In a 20 Gallon Tank (80 liters)? - "Group of Guppies" by timothy.jabez is marked with Public Domain Mark 1.0.
How Many Guppies and Neon Tetras In a 20 Gallon Tank (80 liters)? - "Group of Guppies" by timothy.jabez is marked with Public Domain Mark 1.0.


Embarking on the journey of setting up a captivating aquarium brings with it the joy of curating a vibrant underwater community. As aspiring aquarists delve into the realm of tropical fish, a common question arises: how many guppies and neon tetras in a 20-gallon tank (80 liters) should you have? This inquiry marks the initial step in creating a harmonious environment where the lively hues and dynamic behaviors of these popular species can coalesce into a visually stunning aquatic tapestry. Join us as we explore the key considerations in accommodating guppies and neon tetras within the confines of a carefully crafted 20-gallon (80 liter) aquatic haven.

About Guppies and Neon Tetras


Appearance: Guppies are like living rainbows in your aquarium. The males, especially, boast an impressive array of colors—bright blues, fiery reds, and shimmering yellows. Their tails are often elaborate, with intricate patterns and flowing fins. Females, on the other hand, tend to have more subdued colors, usually in shades of gray or brown.

Behavior: Guppies are social butterflies of the aquatic world. They love to swim in groups, and their lively nature adds a dynamic energy to any aquarium. Males are known for their courting behavior, flaunting their colorful fins to attract the attention of females. Being relatively small in size, guppies are agile swimmers, darting around the tank with grace.

Neon Tetras

Appearance: Neon tetras are the jewel-toned gems of the aquarium. Their bodies are a striking combination of iridescent blue and vibrant red. A distinctive lateral line runs along their sides, creating a glowing effect reminiscent of neon lights—hence the name. Despite their small size, they contribute a big splash of color to any tank.

Behavior: Neon tetras are known for their peaceful and sociable nature. They thrive in schools, and their synchronized swimming is a mesmerizing sight. These fish are not as flashy in their courting rituals as guppies, but they make up for it with their graceful movements. Neon tetras are generally calm and get along well with other non-aggressive tank mates.

In summary, guppies bring a burst of color and lively activity to your aquarium, while neon tetras add an elegant glow with their vibrant hues. Both species are relatively easy to care for and make fantastic additions to community tanks.

How Many Guppies and Neon Tetras In a 20 Gallon Tank (80 liters)?

So, how many guppies and neon tetras in a 20 gallon tank (80 liters) can you keep? When keeping guppies and neon tetras together in a 20-gallon tank (80 liters), it’s important to consider the space and compatibility between the two species. Here’s a balanced suggestion:

Guppies and Neon Tetras Together:

  • Guppies: 6-8 (a mix of males and females)
  • Neon Tetras: 10-12

This combination allows for a lively and colorful community tank. The guppies add a dynamic element with their vibrant colors and active swimming, while the neon tetras contribute their elegant schooling behavior and neon-like glow.

Always keep an eye on the interactions between the fish. Guppies have long fins that might be tempting for nipping, so having enough hiding spots and plants can help provide breaks in their line of sight and reduce potential stress.

As with any aquarium setup, regular monitoring of water parameters, filtration, and the overall health of the fish is crucial. Adjustments may be necessary based on the specific behavior and needs of the individuals in your tank.

Tank Setup

Setting up a 20-gallon (80 liter) tank for both guppies and neon tetras requires careful consideration of their preferences and the need for a harmonious environment. Here’s a step-by-step guide:

  • Substrate: Use a fine-grained substrate like sand or small gravel. Both guppies and neon tetras appreciate a soft substrate, and it allows for the planting of live aquarium plants.
  • Filtration: Install a good quality filter with gentle water flow. Both species prefer well-filtered water with minimal current. Make sure the filter is efficient enough to maintain water quality.
  • Heating: Keep the tank temperature between 72-78°F (22-26°C). Both guppies and neon tetras thrive in tropical temperatures, and a reliable heater will help maintain a stable environment.
  • Decorations: Include plenty of hiding spots and decorations. Guppies appreciate plants and decorations where they can hide, especially females when they need a break from persistent males. Neon tetras feel more secure in a well-decorated tank with places to retreat.
  • Plants: Incorporate live plants. Both guppies and neon tetras benefit from live plants as they provide hiding places, help maintain water quality, and create a natural-looking environment.
  • Lighting: Use subdued lighting. Guppies and neon tetras don’t require intense lighting, and a moderate level of illumination will enhance the colors of your fish without causing stress.
  • Water Parameters: Regularly monitor water parameters such as pH, ammonia, nitrite, and nitrate. Both species prefer slightly acidic to neutral water conditions. Aim for a pH level between 6.5-7.5.
  • Stocking Density: Follow the recommended stocking guidelines mentioned earlier. Keep in mind the space requirements and potential compatibility issues, especially considering the guppies’ long fins.
  • Water Changes: Perform regular water changes to maintain water quality. A 20% water change every 1-2 weeks is a good starting point, but adjust based on your specific tank conditions.

By creating a well-planned and balanced environment, you can enjoy a thriving community tank with the lively and colorful presence of both guppies and neon tetras.

How Many Guppies and Neon Tetras In a 20 Gallon Tank (80 liters)? - "Group of Guppies" by timothy.jabez is marked with Public Domain Mark 1.0.
How Many Guppies and Neon Tetras In a 20 Gallon Tank (80 liters)? – “Group of Guppies” by timothy.jabez is marked with Public Domain Mark 1.0.

Diet and Feeding

When keeping guppies and neon tetras together, you can provide a diet that suits the needs of both species. Here’s a combined feeding guide:

  • Staple Diet: Use a high-quality flake or pellet food as the staple of their diet. Look for a product designed for tropical community fish.
  • Live or Frozen Foods: Offer occasional live or frozen treats like brine shrimp, daphnia, or bloodworms. These foods provide a variety of nutrients and mimic their natural diets.
  • Vegetables: Provide blanched vegetables like spinach or zucchini as an occasional treat. Cut them into small, bite-sized pieces that both guppies and neon tetras can easily consume.
  • Feeding Frequency: Feed small amounts 2-3 times a day. This helps prevent overeating, maintains good water quality, and accommodates the small stomachs of both guppies and neon tetras.
  • Observation and Adjustments: Pay attention to the behavior and appearance of your fish. Adjust their diet based on their needs, and consider factors like age, breeding status, and individual preferences.

By offering a balanced and varied diet, you ensure that both guppies and neon tetras receive the necessary nutrients for their health and well-being. Remember to avoid overfeeding and remove any uneaten food promptly to maintain water quality in your tank.


In conclusion, creating a harmonious environment for guppies and neon tetras in a 20-gallon (80 liter) tank requires thoughtful consideration of their needs. From providing a soft substrate to incorporating live plants and offering a balanced diet, each element contributes to the overall well-being of these vibrant aquatic companions. When deciding how many guppies and neon tetras in a 20-gallon tank (80 liters) to keep, a balanced approach is crucial. Aim for a community of 6-8 guppies and 10-12 neon tetras, ensuring a dynamic and visually appealing aquarium where the lively colors and behaviors of both species can thrive. By maintaining a well-maintained tank and observing the interactions between these friendly aquatic neighbors, you can enjoy a captivating and flourishing underwater world.