Aquarium lighting is pretty overwhelming. Especially if you’re new to the aquarium hobby, picking out the right aquarium light for your fish tank can sometimes be confusing.  Aquarium lighting can have many implications on how your tank looks.

So here, we discuss the key points about aquarium lighting for beginner fish keepers. But if you are setting up a high-tech planted aquarium or a saltwater aquarium, it`s somewhat different. 

Read our “Complete Guide to Planted Aquarium Lighting” to learn more about the lighting parameters used in planted aquariums.

Do fish need lights in the aquarium?

Fish do not need extra aquarium lights. In a freshwater aquarium, the ambient lights in the surrounding is enough for fish to thrive or survive.

But, if you do have your aquariums in a room that is dark a lot, then you may want to turn your aquarium lights on occasionally because no one wants to be in the dark all the time.

Why do aquariums need lights?

Aquarium lights are important for a freshwater tank in several aspects.

Aquarium Setup
Aquarium Setup

As aquarium hobbyists, we need lights to explore our tanks. We love to enjoy the way how fish swim around the aquarium and weave through rocks and plants. It is really entertaining and we need enough lighting to see all those things.

As well as, We all know plants don’t grow in the dark. All aquarium plants need lights to grow themselves with the photosynthesis process, which means they absorb light. 

But not all plants require the same level of light. Some plants like Anubius and java fern can thrive in lower lights, while others, like dwarf baby tears, require super bright lights.

So with some low-light plants, you get to have nice plants and get that natural look with all the benefits they bring, and you don’t have to buy a super bright light that’ll stress out your fish and make them all hide all the time. Also, the lower light plants are much easier to keep.

Aquarium light Types & Fixtures

Shape-wise, there are three different types of aquarium light fixtures. 

First, there are lights that can be put on the side of the fish tank, which have legs that fit perfectly. These are restricted in size, so you can`t setup a 60cm light into a 60cm tank. 

Side mounted Aquarium lights
Side mounted Aquarium lights

The second option is the adjustable length aquarium lights.  You can pull out the holding legs as they match the length of your aquarium. But you have to be a bit careful because if you fit a 60cm light on a 90cm tank, the corners are gonna be too dark. So it’s never gonna be perfect light all around the tank. 

Adjustable length aquarium lights
Adjustable length aquarium lights

The third option is the hanging lights. With hanging lights, you have some clear space to reach into the tank, which you don’t have with any other option. As well as, you can balance out the power of the light by bringing it higher or lower. 

Hanging type aquarium lights
Hanging lights

Considering the technology, the T5 tube lights and LED lights are the two main aquarium light types. 

Some time ago, we had the T8 tube lights and the HQI lights, which disappeared from the hobby. HQI lights had a really specific and emotional light, which we lost because they’re just too big and too hot. 

The production of those aquarium lights is not environmentally friendly. So now we’re stuck with LED and T5 tube lights which are more efficient than previous types.

LED Aquarium Lights

Aquarium LED lights
Aquarium LED lights

LED lights are becoming the most popular aquarium light, among other technologies. Their high efficiency, long life span, and perfect color spectrum make them more reliable.

There’s a misconception about LEDs that they don’t generate heat. That’s not true, LEDs generate a lot of heat. But all these lights are designed in a way that they have heatsinks over the LEDs, and the heatsink can make it easier for the light to release that heat. Some really big LED lights come with even fans in them. 

T5 Tube Lights

T5 Aquarium tube lights
T5 Aquarium tube lights

Compared to fluorescent lamps and T8 tube lights, T5 tube lights perform well. There are different color temperatures that can be selected according to your preferences.

What color lighting is best for fish?

You may have seen different colors of lights like bluish-white and yellowish white. Those color variations occur due to slight changes in the color spectrum of the different types of aquarium lights.

Actually, aquarium lights’ color spectrum is not much important. Both plants and fish can thrive under a wide range of Kelvin. The color temperature of the aquarium lights mainly depends on human preferences.

Many people prefer to simulate a natural environment in their aquariums. So, it’s better to select an aquarium light in white color around 6500 to 7000-Kelvin range.

Why should you avoid excess lights in your aquarium?

We know that lighting is super important in plant growth and algae is also a kind of plant. So Having too much light in your aquarium will promote algae growth.

If we have a lot of nutrients in the tank like fish waste, algae is gonna thrive on that, and when you introduce a lot of high-powered lighting, that’s just gonna make it explode. 

As well as, high-power lights can cause stress out your fish.

Should fish tanks be dark at night?

In the wild, fish experience day and night, and they have adjusted their lives according to that nature. Although most aquarium fish are not from the wild, it’s better if they can be provided with natural environmental conditions.

So it’s recommended to maintain a schedule for the aquarium lighting. The lighting in an aquarium doesn’t have to follow the same day-night cycle at outside. You can have the lights on when you’re at home and when you’re enjoying the tank. But there should be a certain time period with no lights. 

How long should my aquarium light be on?

Normally it is recommended to turn on the lights around 8 hours per day. Otherwise, it is difficult to control the Algae growth in the aquarium. The maximum duration for the light on time can vary according to light intensity, tank setup, and many more factors.

So if you have really powerful lighting, don’t have it on for more than 7 hours a day. If you have less powered lights, you can go up to 8-8.5 hours. But never go more than 10 hours.

You can use external timers to automate the lighting process in your aquarium. As well as, there are smart aquarium lights with built in day night timers and adjustable color options with mobile applications.

App controlled aquarium lights
App controlled aquarium lights

Do aquarium fish prefer light or dark?

Some fish varieties like Discuss fish appreciate less lighting. Watching their behavior is a good way to test whether your fish doesn’t like lights. If you see them constantly hiding under decorations when the lights are on, maybe they’re trying to get away from the lights. 

See what they do when you turn the lights off. If they come out and start exploring all over the place, that might be them telling you they prefer not to have high-powered aquarium lights. So you should consider changing your aquarium lights with low light intensity lights.

What type of lighting is best for aquariums?

Deciding the right aquarium light for your fish tank depends on several factors, such as aquarium setup, plant types, fish habitats, and many more. In addition, your budget and the reliability of the light should be considered.

Sometimes you will get an aquarium light with your aquarium kit itself or get a cheap light from your local store. But most of them are not strong enough or do not last very long. 

As a common, for a beginner-level aquarium with low or medium light plants, Normal LED type aquarium lights can be used. Aqueon LED lights, Fluval aquarium lights, Finnex Stingray LED Lights, and Hygger LED aquarium lights are some of the leading aquarium light types in the hobby.

Aquarium Light Types
Aquarium Light Types

Some people build their own aquarium lights. Because lighting can get somewhat expensive. Actually, DIY aquarium lights are Ok for normal aquariums. But if you are building a planted aquarium or a saltwater aquarium, it’s better to get a properly designed aquarium light with the right parameters. 

Read our “Complete Guide to Planted Aquarium Lighting” to learn more about the lighting parameters used in planted aquariums.

References & PC: Green Aqua


I am Prasanjaya who is an aquarium hobbyist for nearly a decade. I wish to help fishkeepers to get accurate and helpful information regarding every aspect of fishkeeping.

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