Care Guide for GloFish – Fluorescent Fish For Beginners


Care Guide for GloFish – Fluorescent Fish for Beginners

You may have seen brightly-colored fish in a pet shop and wondered what they were. The GloFish(r), a very popular fish among beginners, is because of their amazing rainbow colors, energetic behavior and resilience to living in all kinds of water conditions. Learn how they got their bright fluorescent glow and how you can care for them to live a long, healthy life.


What is GloFish?

GloFish is not one species of fish, but a collection of freshwater fish that have been genetically modified using fluorescent protein genes that are naturally found in corals, jellyfish, and sea anemones. They were originally developed by scientists to study genetics and help detect certain pollutants in the water, but their dazzling appearance made them a popular addition to the aquarium fish industry. The GloFish glows under blue light thanks to their fluorescent genes. This does not seem to affect their quality of living.

GloFish are currently available in the following options. But, new colors and varieties are constantly being developed.

– Zebra danios (Danio rerio) – Black skirt tetras (Gymnocorymbus ternetzi) – Tiger barbs (Puntius tetrazona) – Rainbow shark (Epalzeorhynchos frenatum) – Betta fish (Betta splendens)

Each species has a different husbandry, but we will attempt to give a general overview of their care needs.

GloFish tetras, which are genetically modified black tetras with blue glow, can be found under blue lighting.

What colors are GloFish available? They come in Moonrise Pink and Starfire Red, Sunburst Oranges, Electric Greens, Cosmic Blues, and Galactic Purple.

Are GloFish injected with dye? Their brilliant coloration is not due to injection with dye. It is a hereditary trait passed from parent-to-offspring.

Is it legal to breed GloFish fish? GloFish are trademarked and patented by GloFish LLC, so only they and their affiliates are legally allowed to breed and sell them. If your fish accidentally reproduce in your home or school aquarium, it is not a problem. However, the sale, barter, or trade of GloFish offspring by hobbyists and other unlicensed entities is strictly prohibited.

What is the lifespan of a GloFish? It depends on the species, but on average, these fish live approximately 3-5 years. The lifespan of betta fish is usually between 2 and 3 years. However, some hobbyists have been able to keep rainbow sharks for up to 13 year.

How much do GloFish cost? GloFish can be more expensive than normal-colored fish. At the time of this article, they range in cost from $6.49 for a GloFish danio to $24.99 for a premium male GloFish betta.

How Do You Set Up a GloFish Aquarium?

Most GloFish aquarium kits are quite small, where 10 or 20 gallons seems to the biggest size that is available at mainstream pet stores. However, most GloFish are very active and need to be kept in 20- to 40-gallon aquariums or larger. Also, the blue light that comes with GloFish tanks does not grow aquarium plants very well, which means you may need to add lots of aquarium decorations and fake plants to prevent any aggression among your fish.

GloFish still look very colorful under normal white light and would do well in a beautiful planted aquarium.

A smaller fish tank with no plants will require lots of water changes and filter maintenance to make sure your fish are not living in water polluted by their own waste. Use water test strips to check the water quality and determine if your tank needs cleaning. If possible, buy a bigger aquarium that is not specifically for GloFish. You can use it as long as the aquarium has a “moonlight”, setting that emits blue light, and a white light setting. Then you can add low light aquarium plants that grow under white light during the daytime and naturally consume the toxic nitrogen chemicals produced by your fish’s waste. A large fish tank with many plants will keep your fish’s health better and the water more clean.

Should I turn off my GloFish light? Yes, do not leave the blue light on for 24 hours a day because the fish need to sleep in the dark at night and algae can grow if you turn on the aquarium light more than 12 hours a day. If you find that your fish tank is experiencing green water or excessive algae growth, use a power outlet timer for the aquarium light and number the amount of hours the light is on each day.

GloFish require a heater to keep them warm. Keep them at room temperature between 68-72degF (20-22degC) to avoid them getting sick. A simple aquarium heater will automatically take care of the temperature for you.

How many GloFish should be kept together? You should keep at least six GloFish together. Tetras, barbs, and danios are schooling fish. This will make them more comfortable and reduce aggression. It is okay to have different colors. You could for instance get one tetra each of the following colors to form a six-member school. Tiger barbs can attack other GloFish types, making them semi-aggressive fish. We recommend keeping them in a species-only aquarium that only contains tiger barbs.

GloFish is a fast-swimming schooling fish which gets along with other peaceful, communal fish.

Rainbow sharks grow up to 6 inches (15 cm) long and can be a bit territorial, so we only recommend getting one for a 29-gallon or larger aquarium. We recommend that you only get one Betta fish for your 5-gallon or larger fish tank. They are semi-aggressive, and will not tolerate other GloFish types. See our recommendations for tank mates that you could keep with betta fish.

What are GloFish’s favorite foods?

Fortunately, Glofish are very easy to feed and would love it if you provided them a diverse variety of nutritious foods to eat, such as flakes, pellets, frozen foods, and gel food. Betta fish might be the only caveat because they do prefer to eat from the water surface, so try feeding them floating betta pellets, freeze-dried foods, and frozen foods.

Feed different kinds of fish foods each week to ensure that your GloFish get all the essential nutrients they need for optimal health and coloration.

GloFish are difficult to keep alive

The developers of GloFish deliberately chose the hardiest, most beginner-friendly species possible to make GloFish, so in general, they are fairly bulletproof as long as you keep their aquarium clean and feed them well. However, newly purchased GloFish are sometimes underweight and stressed out, which makes them more susceptible to illnesses. Choose GloFish with rounded bellies that swim well and don’t show any signs (e.g., white spots or ripped fins) and who behave normally. We recommend quarantining all new fish that you bring into your home to prevent the potential spread of disease to your aquariums and to treat them more easily with medication if needed. Also, make sure to keep them in larger aquariums of at least 5 gallons for a betta fish, 20 gallons for tetras and danios, 30 gallons for tiger barbs, and 30-40 gallons for a rainbow shark.

All the best with your new GloFish. Our Aquarium Co-Op retail store does not sell GloFish because we believe there is already a huge variety of colorful fish in nature to choose from. To order aquarium fish online, check out our recommended fish sellers below.