ultimate led aquarium lighting guide

The Ultimate LED Aquarium Lighting Guide

LED aquarium lights have improved leaps and bounds since they were first introduced for aquariums. We have tested hundreds of units over the years and received feedback from dozens of customers all with the aim of putting together the ultimate LED aquarium guide.

Why is Lighting Important for Aquariums?

Aquarium lighting creates ideal growing conditions that try to simulate natural sunlight. Many aquarium inhabitants require light to survive. Planted aquarium lights provide the necessary light for photosynthetic plants which help raise the oxygen levels for fish and other animals in the tank.

If you plan on having plants, anemones or corals you will certainly need a high quality aquarium lighting system. Proper lighting can also improve fish behavior and how much they are able to grow just as it would in nature.

Benefits of LED Aquarium Lights

LED lights have many benefits compared to other lighting types. Chief among them is the amount you will save on your energy bill. We have noted a 75% decrease in our bill since switching to LED. Beyond saving money the ability to have nocturnal lighting and a programmable 24/7 schedule, like the one that comes with the Finnex Planted+ 24/7, makes replicating natural conditions very simple.

Most other lighting types will require you to turn lights on and off every 12 or so hours. This is not only annoying but does not really replicate sunlight. Natural sunlight varies in intensity throughout the day. Some newer LED lighting systems even come equipped with cloudy day settings to further enhance the natural setting.

Many species of fish are nocturnal so you won’t even see them out with a traditional 12 on 12 off setting. Nocturnal lighting with LEDs simulates moonlight so you can still see in your aquarium.

Benefits of LED lights:

  • Less energy consumption
  • Less Heat
  • Last longer
  • Dimmable
  • Nocturnal Lighting

Benefits of LED Aquarium lights vs Other Types?

Incandescent Bulbs

  • Incandescent light bulbs are only able to provide light for smaller aquariums or fish bowls. They are extremely inefficient light sources. If you used enough of these to actually cover a full size tank your energy bill would be very high. They also give off a ton of heat. Enough heat that you would need an aquarium chiller like the one below.

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Standard Fluorescent

  • Standard Fluorescent lights are able to provide enough light for fresh or saltwater fish tanks that only need low light levels. This means you will have to carefully consider which plants to choose as some require medium to high level lighting. Compared to incandescent lighting fluorescent lights produce very little heat and are more energy efficient.

Compact Fluorescent

  • Much like standard fluorescent lights, compact fluorescent lights provide a good amount of light but in a much smaller size. Compact fluorescent lights are commonly prepackaged in aquarium hoods, like the one below. as they are easy for manufacturers to install. They do provide a good amount of light and are suitable for deeper aquariums.

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Metal Halide

  • Metal halide lights are a great option for tropical fish tank setups. They provide a ton of light and heat. This helps replicate the climate that tropical fish live in out in the wild. Beyond the heat and light output Metal Halide offers very little benefits over LED lighting. Because they produce so much heat you will need to setup fans and add an aquarium chiller to limit the risk of overheating. The spectrum range of metal halide is also limited as it only offers one range of light temperature.

Sunny Window

  • Looking for a free aquarium lighting system? Why not try the sun? Well sunlight is indeed a great source of light but you run the great risk of algae growth. As you probably can’t regulate the amount of sunlight it will be hard to control or limit algae growth. Beyond that many people lack access within their homes to an open area by a window. Some try to use skylights but they do not provide enough direct light for many planted aquariums.

How to Choose LED Lights for Aquariums

Measure Your Tank

  • Beyond the obvious concern of price, the first thing to consider when purchasing a LED aquarium lighting system is the size of your tank. Most LED lighting systems come in various sizes that are suited for the size tank it will fit on. This is common with LED light strip style systems. These attach to your tank and have arms that can be tightened or fastened to the walls of your tank.
  • Other LED lights such as the VIPARSPECTRA hang above your tank. This may seem like a one size fits all approach but you have to keep in mind how the light dissipates. Directly under the light will be fine but if you have a larger tank light might not reach the corners. If this is the case you may look for a larger LED or consider daisy chaining two if possible.

Plant and Animal type

  • Another important consideration is the type of plants or animals you will be trying to grow in your aquarium. LED lights have improved greatly over the past few years and most can support marine, freshwater and even heavily planted aquariums. You will still need to research the type of light that your LED can produce and crosscheck that with your desired plants. To error on the side of caution it is always wise to start with low light plants to make sure your LED can handle those and then upgrade as needed.
  • In general it is more important to try and grow plants that you want rather than what your light would handle. The whole point of our hobby is to do something we enjoy. So we always choose our planted aquarium plants first and then see what light will support it. Many hobbyist get annoyed that they can’t plant what they want because they already committed to a specific LED light. I guess the point is to plan and research well before dropping a ton of money only to be disappointed.

Intensity and Spectrum of light you want

  • Not all LED lights are created equal. Or maybe some are more equal than others? When doing your initial research a great deal of numbers will be thrown at you that most people will overlook because they seem to mean nothing or look like marketing talk. Some are important while others not so much. Intensity and spectrum are two numbers you will want to understand and pay attention to before making a purchase.
  • Intensity is a measure of how much light is given off by your LED. This can be measured in a couple of different ways. Wattage and PAR are the two most common. We explain these in further detail below but for now let’s just say the higher wattage and PAR ranking the better. When we say better we also have to consider tank size. 10000W would be overkill, literally, for a fish bowl but might work well for a massive tank.
  • Spectrum is a word that is thrown out there all the time when researching LED lights or any lights for that matter. You will commonly see “Full Spectrum” advertised. What they are trying to say is that their configuration of LEDs provides the same spectrum of color/heat as the Sun. While some come close it is impossible to achieve. The main thing you want to consider is what part of the spectrum actually helps growth or photosynthetic plants. We cover that below as well.

How do LED aquarium lights work?

LED lights

  • LED lights are essentially diodes. Hence LEDs being an acronym for Light Emitting Diodes. These diodes become “activated” when connected to electricity. Electrons are then converted into photons which are basically a focused energy that human and animal eyes perceive as light at a specific wavelength. Still with me? LEDs emit light at different wavelengths and create a series. A series is a combination of a bunch of tiny lights that join together and create the glow we see.

PAR rating

  • Photosynthetically Active Radiation (PAR) correlates to the fraction of sunlight within the spectral range of 400 to 700 nm. Or at least that is what Wikipedia says. What we need to know as aquarium hobbyists is that the photosynthetic response to different levels of PAR varies with plant species and leaf position. Meaning some plants need an LED aquarium light with the ability to produce a PAR rating different than other plants.
  • Exposing plants to prolonged conditions that are not ideal for their growth will cause them to grow weakly if at all. So it is important to research your desired plants and animals before committing to a specific aquarium LED light.

Full spectrum

  • Full spectrum refers to light that covers the electromagnetic spectrum ranging from infrared to almost ultraviolet. This encompasses all light wavelengths that are useful for animal and plant life.
  • Be sure to measure or research what part of the electromagnetic spectrum your full spectrum light actually produces. Some will produce a ton of light at the 300 nm rating which does little help to grow plants. In other words, when companies advertise their product as full spectrum it doesn’t always mean the light range is useful for plant growth.


  • Dimmable is a key feature that separates quality aquarium lighting systems from the rest. The ability to dim lights, or reduce/increase, light intensity is essential for optimal plant growth. Newer Fish Tank LED lighting specific systems allow you to control multiple channels. These channels can be different colors or light intensity.  

Common complaints about LED aquarium lights

Not enough light

  • LED lights tend not to be as bright or as intense as Metal Halide lights. This isn’t always a bad thing as most plants do not require high light levels. If they do you can purchase LED lights with higher ratings. Metal Halide lights also produce a ton of heat so you will need to buy tank chillers which can be a pain to setup and maintain.

Hard to program

  • Some people find the dimmable feature to be confusing and hard to program. While some LED lighting systems allow you to program different settings that can replicate the sun’s color and intensity throughout the day. If you have trouble with electronics we suggest using one with preset intervals instead of fumbling through all the programming.

Need multiple units for larger tank

  • LEDs tend to concentrate the light more than other light bulb types which works great for smaller tanks. However, larger tanks may need the light to cover more area. This will result in having to install more than one LED aquarium light setup. Some units allow for daisy chaining. Daisy chaining allows you to “string” the units together with a single connector wire to eliminate all the extra cords multiple LED units would require.  

Not waterproof

  • While most LED lights say they are waterproof we would say they are more water resistant. Meaning they can handle a splash or two but they will be ruined if fully submerged. This shouldn’t be a problem for most users but you should careful if you have cats or other things that might disturb the lights.

LED Aquarium Lighting FAQ

What plants are easy to grow with LED lighting?

  • Anacharis
  • Sagittaria
  • Vallisneria
  • Ambulia
  • Ludwegia
  • Cyptocoryne Willisii
  • Aponogeton Undulatum
  • Amazon Sword Plant
  • Hygrophila

How Long Should Aquarium Lights Be Left On?

  • 10-12 Hours a day if you don’t have a programmable LED aquarium.
  • If you begin to see algae build up you should decrease the periods of light. This will help prevent the algae growth.
  • Always pay attention to how your lights effect existing plants when transitioning from one light to another. Some of the dimmable LED lights can be set to gradually increase to help with the transition. This is especially important if you are going from a weaker light to a more powerful one. Blasting your plants and fish right out of the box will do more harm than good.

Do I need a cooling fan?

  • Unlike most other lighting types you do not always need a cooling fan or aquarium chiller. Some LED aquarium lights come with built in fans. Other will probably not produce enough heat to warrant a cooling fan. To be safe always monitor the LED to prevent overheating and keep a thermometer in the tank to make sure the water temperature does not rise unexpectedly.

Can you build your own?

  • Yes! There are many DIY tutorials online that cover this in more detail. DIY setups are fun to make and often cost a little less. However, when you run into a problem it will be hard to determine the cause. Many of the top fish tank LED lights have a large user base so you can seek them out on forums or Facebook groups to try and find help.

What are the best LED aquarium lights?

  • As you can probably guess by now this is a very subjective answer. You really need to research what you are going to plant and what fish will inhabit your tank. After that determine the size needed and then choose an appropriate LED aquarium light.
  • We compiled a list of our top picks here. Note we chose these based on extensive research and testing but you might find them unsuitable for your needs.


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