Aquarium lights are essential equipment for your fish tank that has many functions besides just providing enough light for you to see your fish. You might be wondering if you can leave your aquarium light on 24/7?
As a general rule, aquarium lights should be kept on for 6 to 12 hours maximum per day. Do not keep your aquarium lights on 24/7, as it can lead to algae outbreaks in the aquarium and disturb fish’s day/night cycle.
There are various reasons why you shouldn’t keep your aquarium light turned on all the time:
- Fish have a day/night cycle: Fish have a day/night cycle in nature, with the majority of fish resting/sleeping at night. In an aquarium, you’re attempting to replicate this natural habitat, and keeping the aquarium light on all the time disrupts this cycle. Your fish will simply be more active and healthy if they have a day and night cycle.
- You will get algae: The major cause for algae in aquariums is too much light. By keeping your aquarium light turned on 24/7 there is a very good chance to get algae in your aquarium. Once you have a major algae outbreak in an aquarium it is very hard to get rid off, and it is best to prevent it in the first place.
- You are wasting electricity: By keeping your aquarium light turned on all the time, even when you are not there to view it, you are wasting electricity and thus money.
Why do I need an aquarium light?
- To be able to see your fish and aquascape: The most obvious reason to have an aquarium light is that it illuminates the aquarium and you can see the aquascape and fish in your aquarium. When a aquarium light is turned on it makes a dramatic difference in the appearance of your aquarium and it can be a focal point in your living room, lounge or bedroom.
- Plants need light for photosynthesis: If you have live plants in your aquarium an aquarium light will provide essential light for the plants to be able to grow.
- Corals need light to grow: In a marine tank corals and other marine life needs light to be able to live and grow.
How long should my aquarium light be on?
Depending on the type of aquarium you have, there will be different time periods when your aquarium lights can be on.
| Type of Aquarium | Photoperiod | Comment |
|---|---|---|
| Tropical with fish only | 6 – 12 hours | You can adjust the time for when at home. |
| Tropical planted tank (Non-Co2) | 8 – 12 hours | Plants need 8 to 12 hours of light to grow. |
| Tropical planted (Co2) | 6 – 8 hours | With more intense lighting and CO2,less time is needed. |
| Coldwater | 8 – 12 hours | Basically the same photoperiod as tropical. |
| Marine | 8 – 12 hours | Depending on the types of corals, you can adjust the photoperiod. |
If you have a tropical aquarium with no live plants and only decorations, you can leave the aquarium lights on for up to 12 hours. As you are not attempting to grow live plants, you can, for example, choose to turn on the lights only for the few hours after work that you are home.
If you have a low-tech planted tank, the plants will require at least eight hours of light. This period can be extended to 12 hours, depending on the growth of the plants and the amount of algae in the aquarium.
If you have a high-tech planted tank with added CO2, the recommendation is to begin with 6 hours of aquarium lighting and gradually increase to 8 hours.
Coldwater as well as marine tanks require a photoperiod of between 8 and 12 hours.
For the majority of people, the photoperiod during which their aquarium lights should be on is approximately 8 hours. This is long enough for your plants to grow steadily, but not long enough to cause algae.
When do you turn your aquarium light on?
You should enjoy looking at your fish and the surrounding aquatic environment you’ve created when you own an aquarium. Having the aquarium light on when you are home, and able to view the aquarium is usually the best option. When you are home, you can turn on the aquarium light and leave it off the rest of the time.
For instance, if you get home at 16h00 and go to bed at 22h00, you can have your aquarium lights turn on at 16h00 and turn off at 21h00. By doing that, you will view the aquarium and get maximum enjoyment from it.
Use a timer for your aquarium lights
A timer is a simple device that allows you to program the period of time during which your aquarium lights turn on and off. There are many advantages of using a timer for your aquarium lights:
- It simplifies the task of turning aquarium lights on and off: You may forget to turn on the aquarium light one day or to turn it off the next. With a timer, you program it once and it will automatically turn the aquarium lights on and off at the same time each day.
- The lights are turned on/off when you are not home: The timer will continue functioning when you are away or on holiday.
- Aquarium lights are on the same period each day: You can minimize algae growth by maintaining a constant photoperiod for your aquarium lights. It’s also simple to make adjustments if, for example, you know your lights are on for ten hours and want to reduce that to eight in order to reduce algae.
Key Takeaways
- Aquarium lights should not be kept on 24/7
- The ideal period for aquarium lights to be on is 6 – 12 hours, depening on the type of aquarium
- By having your aquarium lights on when you are home you can enjoy viewing your aquascape and fish
- By automating the on and off of your aquarium lights with a timer, you can maintain a constant time period for the lights to be on.
