Fish & aquariums: calm in a tank

The aquarium researchers suggested that watching underwater life might bring some of the benefits of nature to people who can’t easily get outdoors, like people in hospitals, care homes or cities.

Fish move slowly and unpredictably, so your eyes have something gentle to follow. Visitors spent almost twice as long watching a full tank as an empty one.

This kind of soft focus can give a busy mind a break from worry or screens.

Most research on animals and health focuses on animals you can touch, like dogs. Fish are different: you can enjoy them without any physical contact, which researchers note may carry less risk.

Fish may suit people who

• Can’t keep cats or dogs where they live
• Have allergies to furry animals
• Prefer quiet company
• Want an animal that doesn’t need walks

In the public aquarium study, most of the drop in heart rate happened in the first five minutes of watching. Heart rates dropped more when the tank had fish in it than when it was empty.

In the public aquarium study, people’s mood improved more when the tank was partly or fully stocked than when it was empty.

In a study of 69 students and trainees, 30 minutes of watching a large saltwater aquarium raised the point at which they felt pain. The effect lasted 10 minutes after they stopped watching.

Only a small part of the research looks at home aquariums. In one survey of 100 fish keepers, 94% reported benefits, most often relaxation. In interviews, fish keepers also named stress relief.

Those same fish keepers named downsides too: fish can’t give the emotional support of other pets, fish die fairly often, and tanks take time and money.

In an older study, older adults given two goldfish at home showed no difference in loneliness, happiness or anxiety compared with others. One measure of blood pressure did fall after six months.

Some studies in the 2019 review used videos of fish rather than live tanks. Live fish may be more engaging, but a video can still be a calm pause.

Ideas

• A public aquarium’s live “fish cam”
• A calm aquarium video while you have a cup of tea
• Nature films about oceans and rivers

Try breathing in as a fish glides one way across the tank and out as it turns and glides back. There’s no right rhythm: just slow down a little.

In one study of 62 residents of dementia care units, aquariums with large, colorful fish were placed in dining rooms. Residents ate significantly more within two weeks, and kept improving over the next six weeks. On average they gained about 1.65 pounds.

A group shown a scenic ocean picture instead showed no change at two weeks. A later study found a similar early boost in eating.

In an older study of 42 dental patients, watching an aquarium before surgery made people feel more comfortable than looking at a poster. Their anxiety seemed lower, but the difference was too small to be sure.

In another study, patients waiting for a hospital procedure in a room with an aquarium showed a trend toward lower anxiety that also wasn’t clear enough to be certain.

In a study of 29 teens living with type 1 diabetes, each was given a betta fish, and feeding it was paired with their own daily health checks. Their blood sugar control improved more than in the usual-care group. Younger teens responded most.

It was a small study, but it shows how caring for a small animal can be used to build healthy habits.

Tips

• Check for free or reduced-price days
• Go on a weekday morning when it’s quieter
• Find a bench in front of a big tank and just sit
• Bring a friend, a child or an older relative

Ideas

• Look for fish in a clear stream from a bridge
• Visit a park pond and watch for fish and ducks
• Explore tide pools at low tide, gently and without taking anything home

Being near water and nature can add to the calm. Just stay safe near water, especially with children.

If you pass a fish tank in a waiting room, restaurant or library, try pausing for a minute to watch. Small moments of calm add up.

• Calming to watch
• Fine for small homes
• No walks or litter boxes
• No physical contact needed
• Quiet

• Fish can die fairly often, which can be upsetting
• Fish can’t offer the same emotional support as a cat or dog
• Tanks need regular water changes and testing
• Set-up and running costs add up

The RSPCA says traditional fish bowls are too small for goldfish and should be avoided. Goldfish need a filtered tank of at least 50 liters (about 13 gallons), and more space as you add fish.

Goldfish typically live about 10 to 15 years with good care, and some varieties can live up to 30. Many don’t reach that because of poor care.

A new tank needs time for helpful bacteria to build up, mostly in the filter, and keep harmful ammonia and nitrite low. This is called the nitrogen cycle.

The RSPCA advises testing the water for ammonia and nitrite every two to three days for the first six weeks, until the cycle is established. After that, testing every one to two weeks is enough.

RSPCA tips for goldfish

• Change 10–25% of the water each week, and clean the gravel
• Add a water conditioner to new tap water before it goes in
• Rinse the filter in old tank water, not tap water
• Don’t over-clean the filter, so helpful bacteria survive

The RSPCA suggests about half the tank have plant cover, with dense planting in some areas and open swimming space in others. Real or artificial plants both reduce stress.

Goldfish are social and should be kept with at least one other goldfish.

A 2019 scientific review concluded that fish experience pain in ways that share similarities with mammals. Fish in pain may stop eating, breathe faster and change their behavior.

The researcher advises handling fish carefully to protect their sensitive skin. Treating fish as living beings, not decorations, is part of good care.

Children younger than 5, adults 65 and older, and people with weakened immune systems are more likely to get seriously ill from these germs. The CDC says children under 5 should not clean or handle aquarium items.

Safe jobs for young kids

• Counting the fish
• Naming the fish
• Watching the fish with a grown-up
• Drawing the tank

CDC tips

• Wear gloves when cleaning the tank
• Pour old tank water into a bathtub, laundry sink or outside, not a kitchen sink
• Clean and disinfect the sink or tub afterwards
• People with weakened immune systems should ask someone else to clean the tank if possible

Wash hands with soap and running water before and after feeding fish or cleaning the tank, and before eating or drinking. If you can’t wash, use a hand sanitizer with at least 60% alcohol.

Some fish have sharp fins, and germs can get in through even small cuts. Wash any wound right away with soap and water.

See a health care provider if a wound gets red, painful, warm or swollen, and tell them you have a fish tank.

Some people feel embarrassed to be upset about a fish. But the routine of care, the quiet company and the bond are real, so the sadness is too.

Ways to help

• Use simple, honest words like “died”
• Let your child say goodbye in their own way
• Draw a picture or plant a flower to remember the fish
• Answer questions calmly, even if they come up again later

Try not to secretly replace the fish. Children often notice, and an honest goodbye helps them learn that sad feelings can be handled.

The CDC says never to release pet fish outdoors. Most die in ponds or rivers, and some can harm native wildlife.

Ways to rehome fish

• Ask another fish keeper
• Ask your vet
• Ask a local aquarium, school or zoo

Fish that stop eating, breathe quickly or act differently may be unwell or in pain. Check the water quality first, then ask a vet who treats fish.

You can call or text 988 to reach the Suicide & Crisis Lifeline, free and 24/7. You can also text HOME to 741741 to reach Crisis Text Line.

findahelpline.com lists free, confidential helplines by country. If someone is in immediate danger, call your local emergency number.

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