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 and how can I help?

GloFish are not just one type of fish but rather a collection of freshwater species that have been genetically modified with fluorescent protein genes that naturally occur in jellyfish, sea anemones, corals, and other marine life. 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. GloFish’s fluorescent genes make them glow brightly under blue light, which does not seem to have any effect on their quality life.

Currently, GloFish are available in the following options, but more varieties and colors are being developed on a regular basis.

– 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 are genetically modified black skirt tetras that glow 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? They are not dye-injected and their bright coloration is a trait passed down from parent to child.

Is it against the law to breed GloFish GloFish LLC trademarks and patents GloFish, which means that only GloFish LLC and its affiliates are legally permitted to breed and sell them. If your fish accidentally reproduce in your home or school aquarium, it is not a problem. It is strictly forbidden to trade, barter, or sell GloFish offspring by hobbyists or other unlicensed entities.

What’s the average lifespan of GloFishes? It all depends on what species you have, but they generally live between 3-5 and 5-7 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 are more expensive than their regular-colored counterparts. They cost $6.49 for a GloFish male betta and $24.99 for one.

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.

Smaller fish tanks with no plants will need more water changes and filter maintenance in order to ensure that your fish do not live in water contaminated by their waste. (Since the waste chemicals are clear in color, use water test strips to determine how dirty your water is and if it’s time for a tank 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 need to be heated. 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 you keep 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. You can get different colors, so for example, you could get one tetra from each color to make a school of six. 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 Danios are fast-swimming, schooling fish that get along well with other peaceful, communitarian 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. Betta fish are also semi-aggressive and won’t do well with the other types of GloFish, so we recommend just getting one for a 5-gallon fish tank or bigger. You can find our recommendations here for tank mates you might keep with bettafish.

What do GloFish Eat?

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. One caveat is that Betta fish prefer to be fed from the water surface. Instead of giving them frozen food, betta pellets or freeze-dried foods, you can try floating betta.

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.

Are GloFish Hard 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. GloFish that have just been purchased can be underweight or stressed, making them more vulnerable to illness. 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.

Best of luck 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.