How to take care of a fish: the ultimate guide for beginners

Updated 15/11/2024

Thinking about welcoming a few fish friends into your life, but unsure on how to care for fish? No worries - here find the ultimate guide on how to take care of a fish for beginners, where we explore feeding needs, tank care, equipment, enrichment and more.

How to take care of a fish

When learning how to look after fish, there are a few key points to consider - take a look below for a few key things to consider before buying your first fish.

• Tank hygiene. As a fish owner, you’ll need to be prepared to keep your tank free of fish poop and debris, and your tank water fresh.
• Tank size. You’ll need to invest in a tank large enough to house your fish at their adult size.
• Water. You’ll need to keep your water at the right temperature and pH balance for your breed of fish. 
• Equipment. Invest in a tank vacuum, thermometer, heater and light bulbs to keep your tank environment correct for your fish.
• Feeding. You’ll need to feed your fish a quality food that’s right for their breed.
• Enrichment. Invest in live plants, tank mates and ornaments to keep your fish entertained.
• Monitoring. Many fish require a specific temperature and pH level for tank water, so you’ll need to be prepared to perform a water test once a month or so, or if you ever notice signs of illness in your fish.
• Avoid transportation. Keep your fish at home when you travel for vacation, and choose a pet sitter to keep your tank clean (which is vital for keeping your fish healthy). Click below to find out how to secure a pet sitter.

Easy fish to take care of

Find a list of some of the easiest pet fish to take care of that are great if you’re a beginner to fish care.

• Goldfish
• Neon tetras
• Freshwater tropical fish
• Cory catfish
• Betta fish
• Platys
• Zebrafish
• Cherry barb

Freshwater vs. saltwater fish

If you’re new to pet parenting, you might be wondering whether freshwater or saltwater fish are right for you. 

Freshwater fish

Freshwater fish - the types of fish found in rivers and lakes - are generally considered more beginner-friendly than saltwater fish. This is because their natural environments are often more changeable, and so their habitat needs tend to be slightly less precise than that of saltwater fish, making them easier to care for if you’re starting out.

Common freshwater fish include Goldfish, Guppies, Zebrafish, Neon Tetra and betta fish - all of which are pretty simple to take care of.

Saltwater fish

Saltwater fish on the other hand, like Clownfish, Angelfish, Butterflyfish, and Damselfish, require specific tank sizes, lighting, filtration, salt levels, and plants to create the perfect ecosystem. This means caring for them properly can be a lot of work. 

So, if you’re wondering how to take care of a fish that’s easy to look after, the best option for beginners is generally freshwater fish. If you’d like a tank of all the colors of the rainbow and don’t mind the extra maintenance, saltwater could be the best way to go.

Feeding your fish

When you’re reading up on how to take care of a fish, it’s well worth noting that the amount, frequency and type of fish food you opt for depends on the breed of fish in your aquarium. Below, we’ll explore a few areas for consideration when feeding your fish - and a few rules of thumb to go by.

• Types of fish food. The most common is dry food for fish, which is most typically in a flake form, but is also found in pellets, sticks, and dried organisms such as plankton and earthworms. Consider whether your fish is a bottom feeder, as if so, floating fish food will not be appropriate for them. Our best advice is for you to speak to your local pet store about your breed of fish, and the food that’s most suitable for them - nutritionally and practically speaking.
• Protein. Most fish eat other fish, so it’s always useful to check the label when choosing your fish food. The first few ingredients should be fish-based, which means they take up the highest proportion of the food’s ingredients. With that said, check the specific dietary needs of your fish before choosing a fish food.
• Carbohydrates. Unlike us humans, fish don’t have any need for carbohydrates in their diet, so if you see a huge portion of the ingredient list taken up by grains, it’s worth looking elsewhere.
• Vitamins and minerals. Most fish are omnivores, which means they require both animal-based protein and plants to stay healthy. Look for a range of vitamins and minerals, such as vitamins A, B, C, D, and K, along with calcium and iron.
• Amount and frequency. The amount of food your fish needs and how often you feed them will depend on your fish’s breed. Be sure to do your research on this before buying your fish - are you able to feed your fish frequently enough? Feeding your fish too much if not needed, could result in an aquarium stacked with decaying fish food.
• Automatic feeders. Some fish owners opt for automatic fish feeders, which keep the amount and frequency of food in the fish tank consistent, and make things easier for you!

Housing your fish: tank and aquarium care

When buying some new fish friends, one of the most important parts you’ll need to get clued-up on when learning how to care for fish is making the right home habitat for them. 

You’ll need to consider your tank’s size, get the right filtration system, optimize the heat and light, and choose a substrate and a range of plants that mimic your fishes’ natural environment.

Choosing a fish tank

Here are a few things to consider when choosing a fish tank that’s right for your breed of fish, the number of fish you’re getting, and the accessories you plan to pad out the aquarium with.

• Size. The first thing you’ll need to consider when choosing a fish tank is the size - how large will your fish grow when adults, and how much space do they need? Ensure they’ve got room to swim, and some. And would you like to kit out your aquarium with plants and enrichment accessories? They all require space, so speak to your fish tank retailer about how many gallons of water you’ll need to house your fish and the accessories you’re after.
• Glass or acrylic. Most fish tanks on the market tend to be glass, which are easier to look after. Acrylic tanks are known to scratch easier, and can be more expensive than glass.
• Position. The tank you choose will also be affected by where you plan on placing it in your home. Be mindful of sunlight - direct sunlight can be harmful for fish, not to mention it encourages algae growth.

Substrate 

Firstly - what is substrate? It’s an essential layer of small pebbles (and many other materials) on the bottom of your fish tank. It’s there to enable helpful bacteria to grow (as part of your aquarium’s essential nitrogen cycle as explained by  Aquarium Co-op), and for plants to grow their roots.

The substrate you opt for shouldn’t mess with your tank’s pH levels too much, so speak to your fish tank retailer about the best type of substrate for your type of fish.

Substrates come in all shapes and sizes - we’ll explore those below, along with some of their benefits and drawbacks.

Types of substrate

• Pebbles. Often the most aesthetically pleasing, but can give way to gaps where dirt and poop can collect.
• Sand. Easy to clean because there is no room for build-up, but isn’t necessarily as pretty as multi-colored pebbles.
• Soil. Can help to maintain the water quality, and is great for growing aquarium plants. Don’t be tempted to use your garden soil though, as this may contain unwanted organisms and bacteria that could be harmful to your fish and their environment.

Aquarium accessories

Now for the fun part - kitting out your aquarium with plants and enrichment accessories that make the tank look awesome, and ensure your fish friend is living their best life.

• Live plants. Choosing live plants can mean a little more maintenance, but they improve the water quality, helping to oxygenate the water and filter out waste products. They also help to maintain the tank’s ecosystem, for both fish and plants. Certain plants will be suitable for certain fish, so research your fish’s natural habitat, and stick to that as best you can when choosing plants.
• Plastic plants. Like live plants, plastic plants give your fish ample opportunity to hide and play. They’re easier to maintain, but don’t provide any of the health benefits that live plants can.
• Ornaments. The possibilities really are endless when it comes to choosing decorations for your fish tank - mimic your fish’s natural habitat with something that creates shelter and produces bubbles. The main rule of thumb is to make sure it’s purchased from a pet shop - accessories not built for fish tanks and aquariums can introduce unwanted chemicals into your fish’s environment, which could be harmful.

Temperature and light

Fish require an exact temperature to stay healthy - a tank too hot or cold could be fatal for your fish. So, do your research on the specific temperature your fish requires, whether they’re tropical or cold water fish, and install a heater (if needed) and thermometer to make sure your tank’s temperature is always optimum.

You’ll also need to choose the right position for your tank so that your fish and any live plants get the light they need. Too much light and the tank could become too hot with algae growing in abundance, too little light and your tank health could suffer. To get the balance just right, invest in a light specific for aquariums and ensure it doesn’t give off any heat.

Cleaning your fish tank

Any fish tank needs a good filtration system - while you’ll still need to clean your fish tank regularly (we’ll get onto how to care for a fish tank shortly), a filter removes fish waste, debris, and helps to prevent disease. Using a filter is also great for any live plants, as it’ll remove any dirt from their immediate environment.

Now we’ve cleared up the need for any aquarium’s filtration system, the next thing you’ll need to consider about fish tank care is cleaning. Larger tanks may not need to be cleaned quite as often as smaller tanks (as dirt and debris tend to be less concentrated). Either way, here are the steps to cleaning the tank you’ll need to roughly follow:

How to clean your fish tank: step-by-step instructions

1. Thoroughly wash your hands before cleaning your tank so that no additional bacteria is added to your fish’s environment.
2. Remove any tank accessories and clean these separately.
3. Clean the tank walls with a glass-safe scrub to remove any debris and algae.
4. Using an aquarium vacuum, suck up any dirt and fish poop from the substrate and any crevices.
5. Remove and replace around 25% of the water in the tank (with treated water) - you’ll never want to completely replace your tank’s water, as this could result in a dramatic temperature and pH change, which can take a while to readjust.
6. Change your filter, following the package instructions - some recommend a change around every 3-4 weeks.
7. Check the ammonia, nitrate and pH levels of your fish tank’s water - there are multiple test kits you can buy online or from your local pet store.
8. Replace any aquarium accessories.

Equipment needed for your fish

Fish care requires a few essential pieces of equipment that’ll ensure your fish is living their best life in an environment suitable for the fish species. Most (if not all) of the equipment you’ll need will be available in pet stores and if not, online. Take a look below for a list of equipment most fish owners will invest in when learning how to take care of a fish:

• Water filtration system
• Aquarium vacuum
• Cleaning brushes and sponges
• Aquarium water test kit
• Bucket for cleaning
• Tank lighting
• Tank thermometer
• Tank heater (if needed)

How to take care of a betta fish

Betta fish are one of the most popular freshwater fish for pet parents, so take a look below for a few starting pointers on how to take care of a betta fish.

• Feeding. Pellets and flakes specifically formulated for betta fish are great, along with dried aquatic organisms as a treat (that betta fish would snack on in the wild).
• Temperature. 75-80 degrees Fahrenheit - water too cold can be fatal.
• Lighting. It’s generally recommended that betta fish have around 14 hours of light per day, with around 10 hours of darkness to allow for rest.
• Other fish. Betta fish tank mates can include snails, shrimp and neon tetras - just ensure there is enough space for all of your fish species to thrive.
• Substrate. Betta fish can thrive in a tank of gravel or aqua soil - it depends on how often you’d like to clean your tank (gravel generally collects debris more easily), and soil is great if you’re also growing live plants.
• Enrichment. If you’re after enrichment for a betta fish, consider tank ornaments like caves, tunnels, live plants and a mirror and live foods that encourage their natural hunting instincts. Having other tank mates can also enrich your fish’s life, as long as they’re considered a safe match.

Signs of a healthy betta fish:

• Brightly colored scales
• Active swimmer
• A good appetite
• Intact fins

Signs of a sick betta fish:

• Swimming in circles
• Fin biting
• Damaged tail
• White spots on their scales or mouth
• Swollen abdomen
• Bulging eyes
• Faded color
• Poor appetite 

If you notice any of the signs above, your first port of call should be your aquarium - carry out a water test to make sure the pH level is right for your betta fish, and check the temperature. You could also invest in live plants which help to improve water quality, clean out your tank and change your fish’s diet to a more natural one (such as bloodworms), rather than manufactured fish flakes or pellets.

Considerations for pet sitters

If you’re a pet sitter and you’re getting clued-up on how to care for a pet fish, firstly, kudos to you! The best thing you can do is to ask the fish owners for a guide on caring for their specific breeds of fish, so that you know all about their feeding and environmental needs. 

If you’re house sitting for a longer period of time, you might need to clean out the tank, so be sure to ask the pet parents for advice ahead of the sit. 

And if you’re feeling all set to care for your next set of fish friends, click below to find out how to secure a house sit - that’s a place to stay across the globe, simply in exchange for pet care.

Buying your fish

Naturally, you’ll want to make sure the fish you choose is happy and healthy before you make a purchase. Always do your research to ensure you buy responsibly. This means avoiding purchasing off the internet, even if the site looks reputable and specializes in selling pets. Signs to look out for when buying a pet fish - as advised by the RSPCA - include dead fish in the tank, cloudy water, split fins, and white spots. These are all signs that the fish aren’t being well-looked after. Always report any sellers you are concerned about, and look elsewhere if you have any concerns.

Meet our veterinary expert, Holly

This article has been checked by veterinarian Holly Anne Hills BVM BVS BVMedSci. After graduating from the University of Nottingham, Holly spent two years working as a farm animal vet. She then spent some time traveling and volunteering in India, working at neutering clinics and with injured street dogs. Holly now works in small animal practice, and balances this with writing, volunteering with the comms team at Vet Sustain, and she is also a marine mammal medic!

Useful resources

• 350+ best fish names for your underwater pal
• 10 fun betta fish facts
• Most common fish names