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Do Glofish Need Light at Night or Do You Turn It Off?

Having a glofish tank is very popular, especially for young children who are fascinated with the many fluorescent colors of the glofish. These tropical fish are very entertaining, but with any fish there are certain light and tank conditions that should be met so they can have their best life.

Quick Answer

Glofish do not need a light at night. In fact, fish need to sleep in the dark, so having the light turned on will disrupt their sleep cycle. On top of this, having an aquarium light on for more than 12 hours a day can actually cause more algae to grow in your tank. This causes a bigger clean up for you and can cause health problems for your fish. 

Glofish are the first genetically modified fish that were originally created to fight pollution, but they turned out to be great household pets. Read on to learn more about the best lighting for your glofish tank.

Do glofish need light all the time?

Glofish do not need light all of the time. In fact, it is recommended to not keep your tank light on for more than 12 hours at a time. This will allow your fish time to sleep, and decrease algae growth.

Do glofish need led light?

Fish are not heavily reliant on what type of light is used in their aquarium. So in short, the answer is no. Glofish do not need an LED light in their tank for survival. However, there is a difference between glofish needing a LED light to thrive, and wanting an LED light to see the fish’s color to the maximum brightness. 

Do glofish need a blue light?

No, glofish do not need a blue LED light to survive. Glofish require lighting with a color temperature ranging from 5,000 to 6,000 Kelvins. So what is the color temperature? Color temperature is what the naked eye sees from the light bulb. Glofish do need actinic lighting. 

Actinic lighting is the part of sunlight that is able to penetrate the water. Most actinic lights are actually blue lights which can actually reduce stress in fish since it mimics moonlight. But didn’t I just say that glofish don’t need blue light? Yes, I did. This is because glofish actually show their vibrant colors best in black light!

While they don’t need blacklight to live, it is best if you always want to see your fish’s beautiful colors. You can even get a light that can switch from blue to black light which can be used between the morning and afternoon.

Orange color tetra Glofish breed

How long do glofish sleep? 

The sleeping pattern of fish is determined by the amount of light they are or are not getting. As mentioned, you should never keep your aquarium light on all day and night because this will disrupt the sleep pattern of your fish. 

Typically, glofish will sleep anywhere between 9-12 hours per night. It is recommended to keep the lights on for 12 hours and off for 12 hours to accommodate this and the fish can get their sleep. 

A light timer may be a good investment if you tend to forget things throughout the day as well. You can set it up to turn the lights off and on in the tank so you no longer have to worry about it!

Do glofish glow in the dark?

Yes, glofish do glow in the dark. However, this is not a natural occurrence. Glofish were actually genetically modified by scientists who added genes to the fish that produce proteins that fluoresce.

When modifying these fish, the intention was to create a species of fish that would be able to detect pollution in the waters. When that didn’t work, they realized that glofish were great as common household pets. However, due to being genetically modified, they are actually illegal to own in some areas. 

On top of this, glofish are technically not all the same species of fish. Interestingly enough, all glofish colors that are genetically modified, can be found in the following species of fish:

  1. Tetras
  2. Rainbow Sharks
  3. Betta Fish
  4. Tiger Barbs
  5. Zebra Fish
  6. Danios

Do glofish need a heater?

All glofish, except danios, require an aquarium heater in their tank for survival. This is because all species are considered to be tropical fish and need to be in a temperature of between 75-80°F to survive.

Looking for more information on aquarium fish?

In that case, make sure to check out our aquatic fish page. There you’ll find everything you need to know about aquarium fish, shrimp & snails.

Do glofish need an air pump?

Yes, an air pump is also needed in an aquarium tank housing glofish. An air pump not only increases oxygen in the tank, but it also creates consistent water movement. This is beneficial to the mental stimulation of the fish because it replicates ocean currents and keeps your fish thriving. 

Speaking of mental stimulation, there are a few other things you can do to increase the stimulation of your fish rather than solely relying on an air pump. Plants, chorro logs, rock caves, and other decor can be placed in the tank for the fish to explore and hide if they need to. 

Do glofish need a filter?

All aquarium tanks should have a filtering system, and this is also true for glofish. Unfortunately, even with lids, several toxins in the air can settle into our fish tanks, causing diseases or even death of fish. Not to mention the numerous toxins and excess waste in tanks when it comes to live plants, algae, and food remains.

If you don’t have a filter in place, your glofish would only be expected to live around 7 days. You can obtain a filter that sits on the edge of the tank, or even a sponge filter if you prefer that.

Do glofish sleep on the bottom of the tank?

Yes, you will find that some glofish will sleep on the bottom of the tank. This actually means they feel safe enough to sleep without being disturbed by other fish, otherwise they would be hiding. You can also see that they will float and move slightly towards the top of the tank.

On the contrary, if you find that your glofish is at the bottom of the tank and gasping for air there could be an imminent problem. This means that there is not enough oxygen in the tank. Make sure that your air pump is working properly, and if you do not have one, get one as soon as possible.

How do I tell if my glofish is sleeping?

There are a few tell tale signs that your glofish are sleeping peacefully:

  • They are laying at the bottom of the tank, or are laying at the bottom of a decoration or plant.
  • They are floating mid-tank motionless for a longer period of time. 
  • They don’t move even when other fish are moving around them, or don’t react to outside noises, or visualizations (such as a small light or tv).
  • They are breathing very slowly. You can tell this by watching their gill movements. 
  • The fish can be in an upright tilted position. 

While these are all signs that your fish is sleeping, it is also interesting to know that fish never enter a REM cycle of sleep and are subconsciously always scanning their surroundings to ensure their safety.