Do Guppies Eat Algae [Guppy’s Dietary Habits]

By Amod Khan

Updated on

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Do guppies eat algae? This question often arises among fish lovers, as the diet of these beloved aquarium fish greatly influences their health and happiness.

Guppies, also known as Poecilia reticulata, are small species of fish that are native to freshwater habitats in South America. 

They are known for their vibrant colors and hardy nature, which makes them a popular choice for aquariums.

In the wild, guppies feed on various small aquatic organisms, such as plankton, crustaceans, and small aquatic insects. 

They are also known to consume algae, but it is not a major part of their diet. Guppies may have a different diet when kept in captivity than they would in the wild. 

In an aquarium, they may have access to a wider variety of food options, including different types of algae.

This is why it is important to understand the natural diet of guppies, and how it changes in captivity.

In this article, we will explore the natural diet of guppies and whether they eat algae in captivity.

Do Guppies Eat Algae?

feeding guppy

Guppies are not primarily algae eaters, but they may eat algae occasionally as part of their omnivorous diet. 

They prefer a varied diet that includes live or frozen foods, such as bloodworms, brine shrimp, and daphnia, along with high-quality flake or pellet foods specifically formulated for them. 

While they may graze on microscopic algae and biofilm in the aquarium, it’s not their main source of nutrition. Providing them with a mix of foods keeps them healthy and full of energy.

Do Baby Guppies Eat Algae?

Baby guppies, also known as fry, don’t typically eat algae as their main source of food. 

Their diet mainly consists of very small organisms like infusoria, newly hatched brine shrimp, and finely crushed flakes or pellets. 

While they may occasionally nibble on microscopic algae and other tiny organisms found in the tank, it’s not a significant part of their diet. 

Providing appropriate food for their small size and nutritional needs ensures healthy growth and development for baby guppies.

Feeding and Nutrition for Guppies: A Complete Food Guide 

  • When you feed your guppies, choose good-quality flakes or pellets made for tropical fish. Look for ones with 40-50% protein, plus carbs, vitamins, and minerals to keep your guppies in good shape.
  • Treat your guppies with live or frozen foods like brine shrimp, bloodworms, daphnia, or mosquito larvae. These are packed with protein and give your guppies a boost, making them livelier.
  • Remember to give them veggies too! Guppies can munch on cooked spinach, zucchini, or cucumber sometimes. These veggies give them fiber, vitamins, and minerals, which are great for their health and digestion.
  • Feed adult guppies a small amount of food two to three times a day. Just give them what they can finish in a few minutes to avoid overeating and keep the water clean. Adjust how much you give them depending on how hungry they seem and how many fish are in the tank.
  • For baby guppies (called fry), feed them tiny pieces of crushed flakes, powdered fry food, or infusoria several times a day. As they grow, start giving them live baby brine shrimp or microworms to help them grow strong and healthy.
  • Watch how your guppies eat and change their diet if needed. If they keep ignoring certain foods or have tummy troubles, try different options.
  • Keep their water clean to help your guppies stay healthy. Take out any leftover food right after feeding to stop the water from getting dirty and causing problems.
  • Give them different foods to keep their meals interesting and balanced.
  • Be careful not to give them too much food, as it can make the water dirty and harm your fish. Clean up any uneaten food a few minutes after feeding to keep their tank tidy.

Keeping your guppies happy and healthy is easy with a mix of different foods. 

Make sure to adjust their meals based on how old they are, how big they’ve grown, and what they like to eat. 

Also, don’t forget to keep their water clean! With the right food and care, your guppies will stay lively and colorful, bringing you joy for a long time.

Understanding The Life Cycle & Reproduction of Guppies

1. Life Cycle:

1.1 Birth

Guppies are unique in that they give birth to live offspring rather than laying eggs. 

A pregnant female guppy can have a considerable number of baby guppies, known as fry, ranging from 20 to 100 in a single birthing session. 

The actual number can vary based on factors such as the guppy’s genetic makeup, age, and overall health.

1.2 Fry Stage

Immediately after birth, guppy fry is already fully developed and capable of swimming and feeding independently. 

Despite this, they are incredibly tiny and vulnerable to being eaten by other fish, making it essential to provide them with hiding spots and a nutritious diet to ensure their survival.

1.3 Juvenile Stage

When baby guppies grow up, they become teenagers, called juveniles. During this phase, their distinctive colors and patterns may start to show up, but they won’t be bright and colorful until they’re fully grown up.

1.4 Sexual Maturity

Guppies typically reach sexual maturity at approximately 2 to 3 months of age. 

However, this timeline can vary depending on factors like the guppies’ diet, the quality of their water environment, and their genetic predispositions.

1.5 Adult Stage

Once guppies reach adulthood, they are ready to engage in breeding activities. 

This stage marks the beginning of their reproductive journey, and they can continue to produce offspring throughout their entire lifespan.

2. Reproduction:

Guppies are famous for their knack for breeding, earning them the nickname “million fish” because of how swiftly they can fill up an aquarium.

2.1 Mating

When guppies have babies, they’re born alive! Unlike some fish that lay eggs, guppies give birth to live babies. 

The male guppy transfers his sperm to the female guppy using a special fin called a gonopodium, and that’s how the process happens inside the female.

2.2 Pregnancy

After a successful romantic encounter, female guppies carry their babies-to-be, known as embryos, inside them. 

This pregnancy phase typically lasts about 4 to 6 weeks, but it can vary based on things like how warm the water is and how clean it stays.

2.3 Giving Birth

When it’s time, the female guppy gives birth to her babies! The birthing happens pretty fast, usually within a few hours.

Female guppies can keep sperm from previous encounters, so they can have more than one group of babies from just one mating session!

2.4 Caring for Fry

Once the babies are born, they’re eager to check out their new home and search for food.

But being tiny in a big place isn’t simple—they’re at risk of becoming another animal’s meal!

That’s why it’s important to provide lots of hiding spots and some leafy plants for protection.

2.5 Repeat Cycle

These fish are good at making babies, with females able to have many batches throughout their lives.

If you’re not careful, your aquarium could turn into a guppy nursery in no time!

Understanding how guppies grow and have babies is important for keeping them happy and healthy in a fish tank.

To make sure your guppies stay healthy and happy, it’s important to give them the right care, keep the water clean, and make sure there aren’t too many of them.

Guppy Habitat and Tank Requirements

1. Tank Size

When it comes to guppy tanks, bigger is usually better. While you can technically keep a couple of guppies in a 5-gallon tank, it’s pretty cramped. 

Ideally, go for a 10-gallon tank for a small group. If you’re planning on having lots of guppies due to their breeding habits, a larger tank like a 20-gallon one is a great choice. 

The bigger the tank, the more space your guppies have to swim around happily, and it also helps keep the water quality stable.

2. Filtration

Clean water is crucial for guppy health. They’re sensitive to toxins like ammonia and nitrites, so a good filter is essential. 

Look for one that efficiently removes waste and keeps the water clear. Opt for a filter with gentle water flow to keep your guppies stress-free.

3. Water Parameters

Guppies prefer their water just right. Maintain a temperature between 75-80°F (24-28°C) with a heater and check it regularly. 

Aim for a pH level between 7.0 and 8.0. If your tap water is soft, consider adding a product like Wonder Shell to boost hardness and minerals. 

Regularly test and adjust water parameters for happy, healthy guppies.

4. Substrate and Decor

Guppies love having places to explore and hide. Choose a sandy or gravelly bottom for your tank—it’s easy to clean and lets your guppies do their natural digging. 

Throw in some real or fake plants, caves, and other decorations to give them spots to hang out and play. 

Just make sure any decorations are smooth to avoid accidentally ripping their delicate fins.  

5. Lighting

Guppies aren’t too picky about lighting, but they do appreciate a regular day-night cycle. LED lights are perfect—they’re energy-efficient and give your tank a nice, natural glow. 

Keep the tank away from direct sunlight though, as it can cause algae to grow too quickly and mess with the water temperature.

6. Taking Care of Your Tank

Keep your tank clean to keep your guppies thriving. Replace 20-30% of the water weekly to remove waste and replenish essential minerals. 

Clean the tank glass, decorations, and filter regularly to prevent algae growth and maintain water clarity.

7. Choosing Tank Mates

Guppies are social and usually get along with other community fish. Avoid aggressive or fin-nipping species. 

Opt for peaceful companions like neon tetras, corydoras catfish, and cherry shrimp. Consider the size and temperament of potential tank mates to ensure compatibility.

If you set up a tank that’s just like their natural home and take good care of it, your guppies will stay healthy and vibrant for a long time.

Signs of a Healthy & Well-Maintained Guppy


Happy and healthy guppies are full of life and colour. They swim around energetically, exploring their tank and getting along well with other fish.

Look for vibrant colors and clear eyes, which indicate good health. Their fins should be intact, without any damage.

Watching them eagerly eat during meals is also a good sign. If they’re nice and chubby, it means they’re eating well.

And if the female guppies are having babies regularly, it means everything is going smoothly.

By paying attention to these things, you can ensure your guppies are happy and doing well in their tank.

List of Common Diseases and Their Symptoms

1. White Spot Disease (Ich)

Small white spots that look like salt grains on the guppy’s body and fins, rubbing against objects, fast gill movement, sluggishness, and loss of appetite.

2. Fin Rot

Fins appearing ragged, torn, or falling apart, redness or swelling around the fin edges, lethargy, decreased appetite.

3. Swim Bladder Disorder

Difficulty staying balanced and buoyant, floating sideways or sinking to the tank bottom, unusual swimming patterns like rolling or spiralling, and reduced appetite.

4. Dropsy

Swollen belly scales sticking out (pineconing), lethargy, decreased appetite, rapid breathing, cloudy or bulging eyes.

5. Velvet Disease

Fine gold or rust-coloured dust or patches on the guppy’s skin, sluggishness, reduced appetite, fast gill movement, and rubbing against tank objects.

6. Fungal Infections

White or grey patches resembling cotton wool on the body or fins, redness or swelling, lethargy, and decreased appetite.

7. Columnaris (Mouth Fungus)

White or grey patches on the guppy’s mouth, frayed or eroded mouth tissue, lethargy, decreased appetite, and breathing difficulties.

8. Parasitic Infections ( Flukes, Worms)

Excessive mucus production, rubbing or scratching against tank objects, weight loss, bloating, white or stringy faeces.

If you notice any of these signs in your guppies, it’s crucial to act swiftly to diagnose and treat the problem. 

Seeking advice from a veterinarian or knowledgeable aquarist can help determine the best steps to ensure your fish’s health and well-being.

Methods for Treatment and Prevention

Here are some ways to keep your guppies healthy and prevent illnesses in their tank:

  1. Medications: If your guppies get sick, there are different medicines you can use to treat them. Just make sure to follow the instructions carefully, either from the manufacturer or your vet, when giving them medication.
  2. Quarantine Tank: If you think one of your guppies is sick, put it in a separate tank right away. This helps stop the illness from spreading to the other fish in your main tank.
  3. Water Quality: Test the water in your tank regularly to make sure it’s just right for your guppies. Keep an eye on things like temperature, pH levels, and levels of ammonia, nitrite, and nitrate. Also, change some of the water in the tank regularly to keep it clean and healthy for your guppies.
  4. Reduce Stress: Try to keep your guppies relaxed and happy. Avoid overcrowding the tank, sudden changes in water conditions, and aggressive tank mates. Having enough hiding spots is important too. Stress can weaken their immune systems, making them more likely to get sick.
  5. Healthy Diet: Feed your guppies a good mix of foods to keep them healthy. High-quality fish food from the store, along with some occasional treats like live or frozen food, gives them all the nutrients they need to stay strong.
  6. Quarantine New Fish: Before adding new fish to your tank, keep them in a separate tank for a while to make sure they’re not sick. This helps stop any illnesses from getting into your main tank and making your guppies sick.
  7. Clean Tank: Keep your tank clean and tidy to prevent bacteria and fungus from growing. Regularly clean the gravel, remove any algae, and clean the tank decorations and filter. A clean environment helps keep your guppies healthy.
  8. Keep Watch: Watch your guppies closely for any changes in how they act, eat, or look. If you notice anything unusual, it’s important to act fast. Treating problems early can help keep your guppies healthy and stop any illnesses from spreading to the other fish.

You can keep your guppies happy and thriving in their tank by following simple steps.

If you’re ever unsure about what to do, don’t hesitate to ask a vet or someone who knows a lot about fish for help.


Guppies are such fun and fulfilling pets, but they need the right care to stay happy and healthy. 

Knowing what they like to eat, where they feel at home, and what keeps them well is super important. 

With good food, a comfy home, and plenty of TLC, you can enjoy your guppies’ beauty and personality for a long time.


Can guppies survive only on algae?

Guppies typically can’t thrive solely on algae. While they may nibble on it occasionally, they require a varied diet that includes protein-rich foods like fish flakes or pellets to stay healthy and vibrant.

Can I leave algae in my fish tank?

Having some algae in your fish tank is generally okay, as it can provide natural grazing opportunities for fish like guppies. However, excessive algae growth can be unsightly and may indicate an imbalance in your tank’s ecosystem, so monitoring and managing it accordingly is essential.

Is hair algae bad for fish?

Hair algae can be problematic if it grows out of control. While some fish, like certain algae-eating species, may nibble on it, excessive hair algae can compete with other aquatic plants for nutrients and oxygen, potentially harming the overall health of your aquarium.

What is the lifespan of a guppy?

The lifespan of a guppy can vary depending on various factors such as genetics, diet, water quality, and tank conditions.
On average, guppies typically live for about 1 to 3 years, but with proper care, they can sometimes live longer up to 4 or 5 years.

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