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Choosing the right LEDs for your Aquarium

If you look up aquarium LEDs, you'll find a lot of information; some of it is based on what was available from a simple eBay search, while at the other end of the spectrum is LED lighting based on scientific principals. What I'm hoping to do here is put all the relevant information in once place so that you can choose what the right LED lighting for your aquarium.

What are your lighting goals?

The first thing you need to decide is what you want to achieve with your lighting. Everyone will want something different. Some may need high power lighting to grow plants or corals, where others may purely be looking for something aesthetic. You could be looking for low, artistic lighting to cast some nice shadows in an Amazon biotope or maybe different coloured lighting to make a show piece of their aquarium. You could even be looking to just replace the current incandescent tubes you have with something that's cheaper to run and longer lasting. There are many possibilities, and I'll do my best to cover them all.

Converting from tubes

If you are simply looking to convert from traditional fluorescent tubes to LEDs, should be able to use the simple 12v strips. I have created a calculator below which you can use to find the right number of LEDs for you. If you have a larger tank or particularly high output tubes, you may want to consider using the functional lighting section of this page to find a better solution.

To calculate this, you will need to look up the tubes you are currently using and find their light output in lumens. This information should be available on the tube manufacturers web site. If not, you can use this document made by Hagen, and find the details of a similar tube of the same length. Different tube also have different light temperatures, and it would be best to try and match this with your LEDs. The colour temperature should be written on the tube it's self or available online. The colour temperature will be in Kelvin, 6000K for example. If you are running multiple tubes, check the colour temperature of each tube. You can add the Lumens together for any matching tubes, but be sure to calculate different the Lumens for different Kelvin values separately. The reason for doing this is so that you can buy LEDs with a Kelvin value that is a close match your tubes you are using.

For my example, I will use a 4' aquarium with 2 x 40watt 48" tubes, 1 x Power-Glo and 1 x Sun-Glo.

  • The Power-Glo emits 1820 lumens and has a temperature of 18000K
  • The Sun-Glo emits 3100 lumens and has a temperature of 4200K

  • 0m of 3528 strips - 0 lumens | 0 watts
  • 0m of 5050 strips - 0 lumens | 0 watts
  • 0m of 5630 strips - 0 lumens | 0 watts

All strips are based on 60 LED per metres.

If I wanted to use 5050 chip LED strips, I would get a 2.5m strip of LEDs the closest to 18000K and a 4.2m strip of LEDs the closest to 4200K I could.

Aesthetic lighting

If your lighting is not needed for plant or coral growth, you can pretty much do what you like. You can have wild colours or nice natural tones to mimic the natural environment or bring out the colours of your fish.

The simplest LEDs for these set-ups would be the 12v strips. These are simple to apply and will only require minimal soldering. The downside of the strips is that you may not get the shimmer effect associated with LED lighting, but this is down the light being emitted at focused points (like LED modules and Metal Halides), rather than along a tube (like T5s).

LED Strips

There are different strips available for sale, each have a different number, such as 5050, which is the type of LEDs on the strips (it's the size of the LED chip in tenths of a millimetre, so a 5050 LED chip is 5mm square). The other numbers that are shown is the number of chips per metre, this is usually either 30 or 60, the 60 being twice as bright, but using twice the watts to power it.


3528 are the lowest level LEDS. A strip of 1 metre with 60 chips per metre will output around 360 lumens and use around 4.8 watts.


5050 are the next brightest LEDS. A strip of 1 metre with 60 chips per metre will output around 900 lumens and use around 14.4 watts.


5630 are the newest and brightest LEDs currently available on strips. A strip of 1 metre with 60 chips per metre will output around 2000 lumens and use around 30 watts.

Natural Lighting

Using the 5 channels of the TC420, you can build a captivating lighting programme for your aquarium, making use of different colours or different angles of lighting to create stunning effects. With non-functional natural lighting, you don't want to go overboard with the brightness as that could just lead to algae or cyanobacterial problems. Adding low light requirement plants like Java Fern can help with this, as can natural algae grazers, but if you're creating a biotope, they will also need to be native to the area you are re-creating.

Functional lighting

If you need your LED lighting to be functional, you can use the calculators below as an estimated guide for a base set-up. I have devised these calculators based on results that I have gathered after a lot of browsing, research, and testing in my own aquariums. They will give an idea about how much lighting is needed for different size aquariums. However, due to LEDs varying from supplier to supplier and different hood configurations, the lighting may need adjustment for your specific set-up; you may find there is not enough or too much light for your system. Again, due to factors such as LED variance, the height of the LEDs above the water etc, you would always benefit from PPFD readings on your actual tank.

Planted Tropical Aquariums

Planted Aquariums fall under a few different categories, depending on your set-up. There are low-tech planted tanks, where you have a soil substrate, a lower output lighting system, and do not dose CO2 or fertilizers. Then there are medium-tech tanks, which have a higher light output and may dose ferts. Then there is high-tech, where you have high output lighting, advanced substrates, and dose CO2 and ferts. All of these types of aquariums have different lighting levels (in output). Too high a lighting output without CO2 can lead to algae or cyanobacterial blooms for example. Typical lighting levels for these types of aquarium are:

  • Low-tech - less than 30 PPFD
  • Mid-tech - 30 to 50 PPFD
  • High-tech - 50 to 70 PPFD, but can be as high as 100

For low-tech tanks, you could get enough light using LED strips using the tools for aesthetic lighting, but I have also included low-tech in the too below.

With a planted tropical tank, there's no need to get too worked up with colour spectrums. Plants do grow better under certain lighting, but this can vary from plant to plant, and also for the best plant results, you would end up with a pink/purple aquarium (the best colour ranges for plants being 390-450nm (blue) and 640-680nm (red)). If you add green tints to this to make it more appealing to the human eye, you pretty much end up with white light. This corroborates with the latest thoughts from planted tank experts, that the best solutions are to use predominantly white light, but make sure that they are bright enough for the plants.

Using a combination of royal blue (440-450nm), cool white (6500K), and warm white (3500K), we can achieve a light that is great on the eye but also provides a boost of light in the 420-470nm range and still has plenty of red in the 640-660nm range. This is the ratio that I'll be suggesting for planted tanks.

W: H: D: | Inches Centimetres

0 440-450nm LEDs | 0 6500K LEDs | 0 4500K LEDs | 0 Watts1 | 0 Lumens2

Marine Reefs

The lighting for marine reef aquariums has to provide the right level and spectrums to feed the corals that you have. The best combination of LED lighting for reefs seems to be a 2:1 ratio of blue to white. The calculators below will give you a good starting point for your LED lighting, there are 2 calculators, basic and advanced. These figures are all based on 3watt LEDs in a luminaire setup. If your lighting is closer to the water surface, you will be able to reduce the number of LEDs that you need.

This calculator will give you a set of LEDs for your aquarium. It uses 7 types of LED, which combine to give corals optimum growth and colour. Ideally, the LEDs in this set-up should be fitted with lenses to give an 80° viewing angle; however, without the lenses it could just be mounted closer to the water's surface. This calculator uses a combination of 3 different whites with Kelvin ratings of 10000K, 6500K, and 4500K, plus Bright Blue (460 - 470nm), Royal Blue (440 - 450nm), Violet(415nm), and Ultraviolet (380-400nm) to show off the amazing colours of your corals and promote growth. Using the the tool below, enter the length and breadth of your aquarium, and it will calculate how many LEDs of each colour you need. This system is based on a 24" tall tank with a luminaire around 10" from the surface.

Length X Breadth | Inches Centimetres

0 10000K White LEDs | 0 6500K White LEDs | 0 4500K White LEDs | 0 Bright Blue LEDs | 0 Royal Blue LEDs | 0 Violet LEDs | 0 Ultra Violet LEDs
0 Watts1 | 0 Lumens2
1 Approximate wattage, total will vary based on exact LEDs used.
2 Approximate lumens, total will vary based on the exact LEDs used. UV Lighting is not represented.