One of the questions that crop up time and time again in fishkeeping is: do fish need light in aquariums? The answer isn’t an easy yes or no. So, we’ve put together all the details you need to know in this blog post.
Do fish need light in aquariums? Cycles of light
Aquarium fish need light to know whether it’s day or night. If you keep your fish in a dark room, they’re unlikely to live as long as they will if you give them the light they need. Keeping your fish in the dark can weaken their immune systems, which will leave them more prone to diseases. A lack of light can also cause some fish, like goldfish, to lose their colour.
Cycles of light are important for fish, just as they are for humans (and many other animals). The natural light in your room will help your fish determine their cycle. But an aquarium light will make this much easier.
As fish need cycles of light, it’s also important not to leave your fish tank light on for too long. Fish need a period of darkness so they can sleep. Well, so they can rest – they don’t sleep in the same way mammals do.
How long should you leave aquarium lights on for?
Aim to give your fish 12 hours of light and 12 hours of darkness each day. However, natural daylight can fill a few of these hours, so you don’t need to turn your aquarium light on for a full 12 hours each day (keep your fish tank out of direct sunlight, though).
Bonus Tip
If you do leave your aquarium light on for a full 12 hours each day, you’ll promote algae growth. Therefore, 8–10 hours is a better target when it comes to how long you should leave your aquarium light on.
If you’re not always around to turn your fish tank light on and off at consistent times, a timer for your aquarium light could be a great option for you. You can pick up a basic timer socket from Wilko or B&M. Or you could use a smart plug for Alexa and Google devices. Alternatively, we sell Fluval Aquasky LED lights, which have their own timer functions.
Do aquarium plants need light?
Light isn’t just important for fish. If you have live plants in your fish tank, light is essential to keep them healthy, too. That’s because plants convert light into essential energy using photosynthesis. We won’t go into detail about this, because we don’t want you to feel like you’re back in a school science lesson (*shudders*). The short version is: aquarium lights are important for plants as well as fish.
Fish and plants aside, an aquarium light illuminates your fish tank and makes it even more beautiful to look at. When you turn fish tank lights on, you can get a much better view of your fish.
So, do fish need light in aquariums? Yes. But only in consistent cycles.
What type of aquarium light do you need?
Most fish tanks come with a light for your fish. While some older tanks come with T5 or T8 fluorescent tubes, modern tanks come with LED lights. You can then buy individual lights when the time comes to replace them. And, if you want to upgrade your fluorescent tube to an LED aquarium light in the meantime, we’ve written a blog post to help you do this. Meanwhile, Juwel fish tank owners who are looking to upgrade to LED will find this blog post more useful.
Most fish tank lights are white. However, remember those Fluval Aquasky LED lights we mentioned earlier? These fish tank lights offer programmable, gradual, 24-hour light-cycle settings, which recreate under-the-sea lighting for your fish at all times of day. You can also use the weather effects to replicate authentic fish habitats.
About Warehouse Aquatics
The Warehouse Aquatics mission is to offer the most choice at the best prices when it comes to your fishes’ wellbeing. We use the products on our website ourselves and are well-versed in all things fish, so we can give you all the advice you need. We’re not just here to sell aquatic supplies. We’re also here to guide you through your journey as a fish owner and enthusiast.
As a small team, we love to hear from our customers, so please do join the Warehouse Aquatics social media community. We’re always up for a chat, and we’d love to share your aquarium photos with our followers.