Guppy Care Guide (2026): Tank Setup, Diet & Lifespan Secrets

Guppies are very easy to care for. Simply providing them with a stable, clean water environment and proper feeding can ensure they live healthily. However, there are also some issues to keep in mind during guppy care, such as food, tank cleaning…

Although they are an easy fish species to care for, if you are a beginner, I recommend you read this article carefully to grasp the basic and advanced techniques of caring for guppies to not only ensure they live healthily but also have a beautiful appearance and long lifespan.

Some basic information about guppies

Scientific name	Poecilia reticulata
Origin	Originated from the South America, Jamaica, and Trinidad regions.
Size	Very small. Males are about 2 – 3 cm long, females are from 2.5 – 4 cm long.
Lifespan	About 1 – 2 years in the wild and 2 – 3 years in captivity (aquarium).

Interestingly, the name Guppy is named after the person who brought this fish species to the British Museum, Robert John Lechmere Guppy.

Appearance of Guppies

Guppies have a small appearance, vibrant colors (especially on the tail and fins), and a clear distinction between males and females.

Male guppies are small, colorful with large, long tail fins, while females are larger, paler in color, and have shorter fins.

How to Distinguish Male and Female Guppies

There are 2 ways to distinguish between male and female guppies: distinguishing through appearance and distinguishing through structure.

How to Distinguish Males and Females Through Appearance

• Male fish: Slender, petite body (2.5 – 3 cm). Extremely vibrant colors (red, yellow, blue, metallic…). Dorsal and tail fins are very large, long, spreading wide gracefully.
• Female fish: Large, rounded body (4 – 5 cm), belly often bloated. Color is mainly silvery-gray or yellowish dark gray, fins are short and small.

How to Distinguish Males and Females Based on Underbelly Anatomy

Distinguishing by underbelly anatomy gives more accurate results than classification through appearance.

You can distinguish male and female guppies through the anal fin or the Gravid Spot.

Distinguishing via the anal fin.

Male fish usually have their anal fin modified into a long and pointed tube (used for mating), while female fish usually have an anal fin shaped like a soft triangle or rounded fan.

Distinguishing via Gravid Spot

Females have a black or dark spot located right near the anal fin (at the rear of the belly). When the female is pregnant, this spot will noticeably enlarge and darken.

If you want to learn more thoroughly about other distinguishing methods, you can refer to this article: How to Tell If a Guppy Is Male or Female.

How to Care for Guppies

Appropriate Tank Size

Guppies are very adaptable and like to swim in schools. If you keep about 5 or 6 fish, a 5-gallon tank is enough.

If you have space, you should choose a 10-gallon tank to make the water more stable and give the fish more swimming space.

Note: Guppies breed very easily and have a fast reproductive rate. Therefore, if you keep them in a small tank (5 gallons), it is best to only keep male fish as they are not only beautiful but also allow for good population control. If you want to keep both males and females, you should choose a larger tank size (10 or 20 gallons).

Stocking Density in the Tank:

The ideal stocking density is 1 fish per 1 – 2 gallons of water, and you should not stock too densely to avoid oxygen deprivation for the fish.

Water Parameters

To maintain a stable water environment for guppies, you need to ensure the parameters in the following table:

Note: The water level in the tank is 6 – 12 inches for the fish to swim and easily get surface oxygen.

Tank Water Change Schedule

• Frequency: Change water 1 – 2 times per week.
• Water change volume: Each time, only change about 1/3 of the water volume in the tank so that the fish do not experience environmental shock.

What Do Guppies Eat?

Guppies are omnivorous fish in the wild. They can eat larvae, dry or frozen food, and vegetables.

Artemia nauplii is a favorite and most nutritious food for guppies, especially fry. For adult fish, you can feed them tubifex worms to help them grow best and also support female fish in carrying eggs well, helping male fish develop very strong tail fins.

Other food forms: high-quality commercially packaged feeds in the form of small pellets or flakes. In addition, vegetables such as pumpkin and soft-boiled greens help fish supplement vitamins and fiber.

Feeding Regime for Guppies

Portions and food sizes need to be flexibly adjusted according to the fish’s growth cycle:

Newborn fry (1 – 3 weeks old): on the first day after birth, you do not need to feed the fish. From the 2nd day, feed 4 – 5 small meals/day. Prioritize small-sized, protein-rich live foods such as newly hatched Artemia nauplii. If using fishmeal, it must be a fine powder type.

Growing fish (4 – 8 weeks old): Feed 2 – 3 meals/day. During this stage, priority should be given to supplementing foods that help fish grow quickly, such as tubifex worms.

Adult fish (over 2 months old): Feed 1 – 2 meals/day. During this stage, besides normal feeding, increase the supplementation of boiled vegetables to add vitamins and fiber to help the fish look beautiful and retain their color well.

Choosing the Right Light and Filter for Guppies

Choosing the right light and filtration system helps fish display beautiful colors, stay healthy, and keeps the water always clean.

Choosing the Right Light for Guppies

You should choose lights with a color temperature of 5,500K – 8,000K (natural white or warm white light) so that the fish’s colors appear most realistic and vibrant. Avoid using overly blue lights above 10,000K (intended for saltwater fish) as they easily cause ecological imbalance and harmful algae growth. The light wattage is shown in the table below:

Note: Turning on the lights for 8 – 10 hours per day is enough, helping fish display beautiful colors and grow well while avoiding harmful algae growth.

Choosing the Right Filter for Guppies

• Weak swimming in guppies: Guppies (especially males) have very large, long, and wide-spreading tail fins. If the water flow from the filter is too strong, the fish will be swept away, forced to swim continuously causing exhaustion, stress, torn fins, and leading to death.
• Protecting fry: Guppies give birth to live young. An overly strong filter (such as high-capacity hang-on-back filters, sump filters) can suck fry into the machine.

Therefore, you should use sponge filters (bio-sponge filters) or mini hang-on-back filters with a flow control valve set to the lowest level.

Filter wattage/capacity table for your reference:

Fish and Plants That Can Be Added to the Tank

Fish

Guppies have a gentle temperament and small size, making them very suitable to keep with peaceful, non-aggressive fish that do not nip fins. Therefore, you can try keeping them with the following fish species:

Plants

Since guppies prefer still or gently flowing water, you should choose easy-to-grow plants that do not require too much light and CO2. Refer to the table below:

How to Treat Common Guppy Diseases

The most common diseases in guppies include white spot (Ich), fin rot/clamped fin, fungus, bloating, and dropsy.

White Spot Disease (Ich)

Symptoms: Tiny white spots resembling grains of salt appear on the body and fins; fish frequently rub themselves against the tank walls.

Cause: Caused by the protozoan parasite Ichthyophthirius multifiliis which proliferates when water temperatures fluctuate unsteadily.

Treatment:

• Increase the water temperature to about 80°F – 86°F (gradually raise it by 2°F per day).
• Change 15% – 25% of the water in the tank daily and thoroughly siphon the bottom sediment.
• Methylene blue can be used according to the manufacturer’s instructions on the product label.

Clamped Fin / Fin Rot Disease

Symptoms: The fish’s tail folds and closes together like a needle (clamped fin) or tears, frays, and gradually shortens (fin rot), and the fish swims sluggishly.

Cause: Polluted water, high ammonia/nitrate levels, excessive water current, or overcrowding.

Treatment:

• Use a heater (if the weather is cold) set to 82°F.
• Change 20% – 30% of the water in the tank every 2 days, siphoning out bottom sediment cleanly.
• Mix rock salt / sea salt (non-iodized) at a ratio of about 7 – 11 grams/gallon of water.

Fungal Disease

Symptoms:

• Water mold (Fungus): White cotton-like tufts appear on the fish’s body, fins, and mouth. The fish feels itchy and frequently rubs itself against the tank walls.
• Gill rot/fungus: The fish swims sluggishly near the water surface, panting. Gill covers are swollen, gill filaments are dark purple or mottled white due to necrosis.

Cause:

• Water source becomes dirty due to accumulated fish waste and leftover food.
• Water temperature changes suddenly or is too cold, causing the fish’s immunity to drop.
• Fish density is too high, the tank lacks oxygen and lacks a stable biological filtration system.

Treatment (Perform in a quarantine tank):

• Temperature: Use a heater to keep water stable at 82°F (28°C) to inhibit fungal growth.
• Oxygen: Turn on a strong air pump continuously to support fish respiration (do not turn it off).
• Specialized medication: Use Bio-Knock 2 (1 drop/10-15 liters of water) or API Pimafix according to the dosage instructions on the packaging.
• Salt: Add non-iodized rock salt at a dilute ratio of 4g – 7g / gallon of water (about 1g – 2g/liter).
• Water change: Change 20% – 30% of the water daily, siphoning the bottom sediment clean. Replenish medication and salt corresponding to the newly changed water volume. Treat continuously for 3 – 5 days.

Bloating and Dropsy Disease

Symptoms:

• Bloating: The fish’s belly swells round like a ball, the fish swims sluggishly, loses balance, or lies motionless at the bottom/surface of the water. The fish stops eating, and may have prolonged white feces.
• Dropsy: The scales on the fish’s body stick up like a pinecone (best seen from above). Often accompanied by bloating and popeye in advanced stages.

Causes:

• Bloating: Caused by the fish eating too much indigestible food (dirty tubifex worms, spoiled leftover food), intestinal bacterial infection (Aeromonas), or internal parasite infection.
• Dropsy: Caused by bacteria attacking and impairing kidney function or internal organs, making the fish unable to excrete water, causing fluid accumulation under the skin which makes the scales stand up.

Treatment (Highest recovery rate when detected early in the bloating stage):

• Quarantine: Net the sick fish into a separate tank for observation and special care. Reduce or temporarily suspend feeding during the first few days to let the fish’s digestive system rest.
• Temperature & Oxygen: Keep water temperature stable with a heater and turn on the air pump continuously to support the fish’s metabolism.
• Use Epsom salt (Magnesium Sulfate): Helps support fluid retention reduction in fish. Epsom salt can be dissolved in water following general aquatic care guidelines. If Epsom salt is not available, non-iodized rock salt can be used at a dilute ratio.
• Supporting products:
  • Mild cases (Bloating due to digestion): Use digestive enzymes specifically for fish or aquatic digestive support products.
  • Severe cases (Dropsy due to internal bacterial infection): Use specialized fish medications following the manufacturer’s instructions on the product label.
• Water change: Perform regular partial water changes daily and siphon bottom sediment clean to maintain a clean water environment.

Frequently Asked Questions (FAQ)