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FISH / new pets

A Set-up Guide for New Algae Eater Fish

Tips for home and health


4 things to know about your new algae eaters

  • They’re living “vacuum cleaners” that snack on aquarium algae
  • They can live between five and 15 years
  • They grow between 2 inches to as large as 2 feet long, depending on species
  • They should live with fish of similar size

Algae eater’s aquarium

Set up the aquarium at least one day before you add any fish.

Aquarium & stand

  • The minimum size of an appropriate aquarium depends on how many fish you have and how big they will be as adults. Fish that are 6 inches long, or under, need at least a 20-gallon tank — bigger fish need more space. The largest algae eaters, such as the common plecostomus (growing up to 20 inches), need at least a 75-gallon tank.
  • 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; so pick a very sturdy, stable base for your aquarium, then fill the tank with water.
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What goes in the fish tank?

  • If you will be using an under-gravel filter, add it first.
  • Layer about 3 inches of gravel on the bottom of the tank. (That works out to 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.
  • Add the thermometer and other necessary equipment.
  • Time to decorate! Add fish furniture, plants, rocks and other objects. Rinse all décor (with dechlorinated water) before adding it to the tank.
  • Finish by filling the tank the rest of the way with dechlorinated water.
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  • An aquarium filter should be able to process all of the water in the tank three to five times an hour. For example, the filter in a 20-gallon tank would need to push through at least 60 gallons of water each hour. Follow the manufacturer’s instructions to choose and set up the filter.
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Heat & light

  • Check the recommended temperature your algae eaters require before you put them in your aquarium.
  • 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 either 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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Adding algae eaters to your aquarium

  • Bring your algae eaters home right away after you buy them.
  • Place them in your aquarium — inside their bag — for 15 minutes so they can get used to the new water temperature.
  • Next, use a net to transfer the algae eaters into your aquarium. Try not to bring too much of their old water with them.
  • Add only three algae eaters at a time to make sure the filter can handle all the new action in the neighborhood.
  • The chemical balance in your aquarium will change with every new fish you introduce, so check the tank’s pH, ammonia, nitrite and nitrate levels regularly.
  • PetSmart stores offer free water testing.
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Feeding Algae Eaters

Feed your new pet algae wafers daily along with occasional supplements of fresh veggies, like sliced zucchini or kale.

Keeping algae eaters healthy

If your algae eaters display any of these symptoms of illness or distress, talk to a PetSmart store associate or a veterinarian familiar with fish health:

  • Decreased appetite
  • Fins clamped to the sides
  • Scraping body on rocks
  • Abdominal swelling
  • Inflamed or discolored skin or fins
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FREE water quality testing

PetSmart offers free aquarium water testing. Bring in a sample and we can test its quality within minutes.

General aquarium health and environment guidelines

  • 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.


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.

The PetSmart Promise: 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.