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FISH / new pets

Community Fish Care Guide

Tips for non-aggressive community tanks


3 things to know about your community fish

  • "Community fish" describes non-aggressive species that can share an aquarium peacefully
  • Fish in this category include the guppy, platy, molly, dwarf gourami, tetra and others
  • Community fish don’t necessarily come from the same part of the world

How do I set up a community fish habitat?

Prepare the aquarium at least 1 day before you add any fish.

Aquarium & stand

  • The size of the aquarium will depend on how many fish you have and how big they will be as adults.
  • The aquarium should be near a power source in a low-traffic area, away from direct sunlight and drafts.
  • Water weighs 8 pounds per gallon. Pick a very sturdy, stable base for the aquarium before filling it.
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What do I put in the aquarium?

  • Layer 1-2 inches of gravel on the bottom of the tank (about 1½ pounds of gravel per gallon of water). Rinse the gravel before putting it in the aquarium.
  • Fill the tank about halfway up with dechlorinated water and add bacteria supplements to promote biological-waste breakdown. Add a thermometer and other necessary equipment.
  • Time to decorate! Add fish furniture, rocks and plants. Rinse all décor before placing it in the tank.
  • Finish by filling the tank the rest of the way with dechlorinated water.
  • Maintain a healthy environment for your fish by testing the water frequently and changing 25 to 30% of the water weekly. If you are unsure about the health of the water, bring a sample to PetSmart for free testing.
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  • Follow the manufacturer’s instructions for choosing and setting up the filter.
  • An aquarium filter should be able to process all of the water in a tank 3 to 5 times an hour. For example, the filter in a 20-gallon tank would need to treat at least 60 gallons of water each hour.
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Heat & light

  • In order to thrive in the same tank, the community fish you choose must be suited to the same basic environment. For example, tropical fish require water temperatures ranging between 73 and 82 degrees Fahrenheit.
  • Choose an aquarium heater with 5 watts of power for each gallon of water in the aquarium. A large aquarium may need a heater at each end.
  • Wait 15 minutes after filling the tank before turning on the heater.
  • Place the heater close enough to the filter to distribute the warmed water.
  • Run the tank’s filter and hood light for 24 hours, then check the water temperature and adjust the heater if necessary.
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What do community fish eat?

Feed your fish flakes or pelleted food twice daily. Use appropriately sized pellets, and only as much food as the fish can consume in 3 minutes. Supplement their diet with frozen or freeze-dried brine shrimp or tubifex worms.

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How can I keep my community fish healthy?

Even after they are settled in, fish can get sick. Contact a veterinarian or a PetSmart store associate if you notice any of the following signs

  • Unusual swimming pattern
  • Thinness or decreased appetite
  • Abdominal swelling
  • Inflamed or discolored skin or fins
  • Fins clamped to sides of body
  • Scraping body on rocks ("flashing")


  • Fish and aquatic animals can transmit disease to humans. Wash your hands with soap and water before and after interacting with your aquarium. Children, pregnant women, elderly people and people with immune-system problems should take extra care.
  • Keep fish away from food and areas where food is prepared.
  • Never release fish into the wild.
  • Adults should assist children with hand washing after contact with a pet, its habitat or aquarium water.
  • Always add dechlorinator or water conditioner to tap water before adding it to the aquarium.
  • Do not use soaps or detergents to clean aquarium or décor, since they are toxic to fish.


Pets purchased at PetSmart are part of our exclusive Vet Assured™ program, designed by PetSmart veterinarians to help improve the health and well being of our pets.

Our vendors meet a high standard in caring for pets and screening them for common illnesses. This program also includes specific standards for in-store pet care.


If your pet becomes ill during the initial 14-day period, or if you’re not satisfied for any reason, PetSmart will gladly replace the pet or refund the purchase price.