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Aquarium lighting can make a huge impact on the success of your tank. A beginning aquarist might overlook this impact at first, relying on natural light or standard-issue incandescent lamps as a means of showing off their fish. However, lighting for aquariums goes far beyond aesthetics and can impact all the living things in your tank- fish, plants, and algae included. Aquarium lighting can impact fish behavior and is essential for the proper growth of aquatic plants. In order to encourage a healthy environment, it is important to look into quality aquarium lighting and options for control that allow for fine-tuning your ecosystem for optimum success.

LED lighting is the best for aquariums in terms of quality and control, and can be used for any aquarium. Incandescent lamps are often less efficient-shining extra light away from your aquarium and can run hot which can be problematic in smaller setups. Fluorescent lamps, while offering some options for the full light spectrum, tend to lose intensity over time. In comparison, LED lights to give you control over the entire light spectrum to influence your animals and plants. They also run cooler than other lights and are long-lasting for minimal maintenance over time. LED lights can last for 50,000 hours- or 6 years- without replacement. Although the up-front cost can be higher than some of the other lighting options mentioned, these powerful lights are energy efficient. In fact, LED bulbs can run on up to 80% less electricity than other lights! The energy efficiency coupled with their long life adds up to serious savings in the long run in comparison to their counterparts. LED lights are also more adjustable than standard bulbs. This means that you can often adjust the spectrum of light coming through and use different color channels to influence your tank. Many LED lights include modes for day and night, as well as modes optimized specifically for plants and reefs.

Finding a suitable LED light for a 125-150 gallon aquarium can be a challenge. With a larger scale setup, more attention must be paid to light coverage and intensity throughout the tank. The light fixtures must have proper dimensions to properly fit the tank, and strike a healthy balance between intensity and luminosity. The lighting that you choose, and the intensity that it can allow, will dictate the type of plants and corals that you can grow in your environment. Luckily, there are plenty of options for great aquarium light setups, not to mention other opportunities for making your own lighting. To figure out what will work best for you, it helps to understand the type of light that you need for your selected plants and fish to thrive.

Light is made up of colors, referred to as a spectrum, that while not overly noticeable to the human eye can have an impact on the aquatic environment. Humans are more sensitive to green and yellow light, whereas plants thrive under red and blue light. Choosing an aquarium lamp that supplies the correct colored light to your tank can have a great impact on photosynthesis that plants use to grow- and lead to a booming, thriving aquascape. A bonus of using LED aquarium lights is that many models give you fine control over the light spectrum, which you can adjust as often as you like to suit your needs. Fish are less sensitive to changes in light, however, it can still have an effect on their lifestyle. It is important for fish health that they have distinct day and night, or light and dark periods every 24 hours. This not only maintains the natural day and night cycles they would experience in the wild, but it gives nocturnal species of fish some space to thrive. Although fish are not overly sensitive to the spectrum of light, studies have shown that fish exposed to red light stimulated feeding motivation. Now that we have a handle on how light works, we can think about some factors to consider when looking for an LED aquarium light for a 125 or 150-gallon aquarium.

108497233 – coral reef aquarium tank scenic shot



As previously stated, a large 125 to 150-gallon tank can be an interesting size to light. Aquariums of this size can have a length of around 6 feet, which can be difficult to outfit properly. When it comes to growing plants and corals, the light coverage must be enough so that the corners aren’t in the dark, which will lead to stunted growth and plant die-off. A standard 60” light, in this instance, might be enough for fish and live rocks but insufficient for coral and plants. In order to provide full coverage for a large planted tank, it can be beneficial to rely on several smaller lights as opposed to fewer large lights. An added benefit of using several smaller lights is that there is less of an emergency if one of them burns out you will have several backup lamps until you can replace it. Smaller lamps are also more affordable to replace than larger light fixtures. Another factor to consider is the degrees of illumination for the light fixture. Many LED lights use lenses to diffuse the light and prevent a spotlight effect, which can help illuminate areas that would otherwise be in shadow. Use the dimensions of your aquarium and your desired plants and livestock as a guide for what configuration of lights would work best for you.


LED lights can become hot to the touch but often run at half the temperature of an incandescent bulb of the same brightness. This is a wonderful feature for aquarium environments, where the lights are meant to be kept on up to 10 hours a day. Older lights such as incandescent and fluorescent lights run the risk of running hot enough to cause temperature changes in your aquarium- which can be disastrous for sensitive fish. LED bulbs run cooler because their design features a heat sink- a component of the bulb that is designed to draw the heat out of the LED and keep the device as cool as possible. This is partly why LED lights wind up having such a long lifespan. Many aquarium light options will give ratings for how hot the lamps get. For a larger aquarium, such as a 125 to 150-gallon tank, using several smaller lights might increase your temperature over time. However, it is unlikely that the temperature differences from LED lights will be hot enough to warrant installing a chiller or fan for your tank.


Most plants and fish need about 8 to 12 hours a day of light. While you can definitely achieve this yourself by turning the lights on and off, a timer is a great feature to look for in aquarium lighting, as it automates this process for you. If your lights are on all the time, it can stress out your fish and also lead to algae buildup. Leaving your lights off is also problematic,  as most aquatic plants need plenty of daylight hours in order to grow and spread. A good timer feature can be helpful in making your aquarium as low maintenance as possible, and you can ‘set it and forget it. For a truly hands-off experience, some LED light fixtures are even designed to be run constantly and have a built-in 24-hour program where they cycle through various lightning to recreate day, night, dawn, and dusk.

If you are using a timer, it’s important to note that not all timers are equally reliable. It’s a good idea to test your timers ever so often to make sure they have not gone out of sync- this is especially important if you have multiple lights to cover a large tank. If one of the lights is not timed right, it could be interrupting the light sequence for the tank and causing disturbances in your ecosystem.

Intensity Control

Another great feature of LED lights is the amount of control available to the aquarist. LED lights are often adjustable so that you have complete control over the percentage of light intensity. This is super helpful when introducing new life to your aquarium, as you can adjust the intensity over time to acclimate them to your environment. With many LED lights you are also given control over the color spectrum for your lighting, meaning you can tweak the spectrum over time depending on what you need. For reef tanks, this saves time and effort as you will not have to move the corals around as much, as you can adjust the light separately for each part of the tank- which is super beneficial to large tanks in the 125 gallons or larger range. Another benefit of adjustable intensity is that you won’t have to worry about fussing around with the height of your lights. Any changes in location can be accommodated without compromising the quality of light for your tank- you can simply adjust the LED intensity as you like to make up the difference. When working with large tanks in the 125 to 150-gallon range, it’s also important to consider the intensity of the lights in relation to the depth of the tank. If you are constructing a heavily planted tank that’s on the deep side, you will need a lamp of high intensity to make sure that light is reaching the plants towards the bottom of the tank.

These parameters can leave a lot up to consider when shopping for aquarium lights. We have mentioned that many of these considerations will depend on the specifics of your tank. An LED light fixture that is designed for a reef tank might look pretty different compared to a heavily planted freshwater setup. However, there are some broad-spectrum lights that work pretty well for a variety of aquariums. We have gathered some recommendations for a variety of aquarium types, to give some insight into possible LED light fixtures for your unique tank.

Lighting a 125/150 Gallon Freshwater Aquarium

For those of you planning on having a 125/150-gallon aquarium that doesn’t need specific lighting, you have the cheapest lighting options available. To cover the entire surface of your 6ft tank, I highly recommend purchasing two 36inch lights.

1. NICREW Classic LED

NICREW Classic LED is a nice practical option for a beginner’s fish tank or a tank that is only lightly planted and does not need much adjustment. It features two modes- day and night (or white light and blue light) that you adjust manually with a switch- although an external single-channel timer is available separately for this product. The white and blue channels of light are great for aquarium plants, and the size of each fixture is adjustable, with the largest fixture being 48-52”. For the largest fixture, you could outfit a larger 125 to 150-gallon tank on a pretty reasonable budget. Here you can find the NICREW Classic LED.


  • White and blue light channels
  • A budget-friendly option for outfitting a larger tank
  • Adjustable brackets to fit a variety of aquarium shapes


  • Timer sold separately, with only one channel capacity

Lighting a 125/150 Gallon Planted Tank

Planted freshwater tanks also need special lighting considerations, though are not quite as fussy as corals. Freshwater aquatic plants can vary from low-high light needs, but all can benefit from an LED aquarium light that produces multiple channels of light. The type of light fixture that you need for your planted tank will depend on how many plants you keep and how sensitive they are, so we will take a look at a few different models for different levels of a planted tank.

1 . Current USA Satellite Plus Pro

For a more sophisticated aquascape or heavily planted tank, the Current USA Satellite Plus Pro is a great choice that offers complete customization. This super bright and full-spectrum light offers adjustable intensity in every color channel, so you can optimize for any particular plant in any location in the tank. It runs on a 24-hour program that includes two 15-minute transitional cycles to simulate sunrise and sunset. Here you can find the Current USA Satellite Plus Pro!


  • Full-spectrum adjustability for complete customization
  • 24 hour light cycle is low maintenance
  • Weather programs inspired by natural environments
  • Large size fixtures available for large tanks


  • One of the more expensive options

The day and night settings are fully adjustable in spectrum and intensity so it can truly be tailored to any aquarium, and it comes with programs that adjust every bulb to create natural-looking light effects such as cloud cover and storm modes. These adjustments are all made from an included remote control. This light fixture comes in a variety of sizes, with the largest being 48-60” adjustable- making it a possibility for even large aquariums. Although the price is a bit on the higher end, the price reflects these premium features.

2. Finnex Planted+ 24/7 LED

For aquarists who have heavily planted tanks but need a slightly more budget-friendly option without sacrificing adjustability, the Finnex Planted+ 24/7 LED Aquarium LED Light is another great choice. It runs on a 24-hour program and is fully adjustable in spectrum and intensity. The 24 cycle includes sunrise and sunset and the super bright daylight settings are designed to promote plant growth. Here you can find the Finnex Planted+ 24/7 LED.


  • A full 24-hour cycle is a low maintenance
  • Fully spectrum adjust-ability for complete customization
  • Weather programs inspired by natural environments


  • Smaller size means multiple light fixtures are needed for larger tanks

It also comes programmed with some weather pattern settings to imitate a natural environment. This fixture comes with a remote control that makes adjustments and programming very straightforward. It comes in a large variety of adjustable sizes, with the largest at “46.5-48”. Compared to the Current USA Satellite Plus Pro, you get a lot of the same functionality- however, the size means you will need multiple units to cover a larger tank.

3. Fluval Plant Spectrum Bluetooth LED 3.0

For a heavily planted tank that demands high-tech and reliable light, another great option is the Fluval Plant Spectrum Bluetooth LED 3.0. This aquarium light is extremely powerful and fully programmable, designed specifically with plants in mind. It runs on a 24-hour program and the LED bulbs in this fixture are High Thermal Efficiency rated, and guaranteed to last. They also boast 120 degrees of illumination, which means your entire tank will be lit uniformly with no dead spots or gaps. Here you can find the Fluval Plant Spectrum Bluetooth LED 3.0.


  • Full-spectrum adjustability for complete customization
  • 24 hour light cycle is low maintenance
  • Preloaded cycles for common tank setups
  • Large size fixtures available for large tanks


  • None!

Although there are several premade lighting cycle options built into this fixture, you can easily program your own. This light fixture is Bluetooth enabled and all adjustments can easily be made remotely from your smartphone. This fixture comes in a few different sizes, with the largest at 60”, which is great for larger aquariums.

These are just a handful of options available to fishkeepers looking to delve into LED lighting. As you can see, lighting a large tank of 125 to 150 gallons can be a challenge. Although the size of the light fixture can play a part in your decision, bigger is not always better and every setup is unique. In many instances, several smaller lights can be more efficient and affordable than one or two large lights. Aside from being better able to uniformly spread light around, having several light fixtures can also give you some leeway when it comes to maintenance. If one light fixture burns out, you will still have plenty of light to keep things afloat until they can be replaced. It is also worth mentioning that replacing one smaller light fixture will likely cost less than replacing one of the larger ones.

Although we have been mostly discussing tank length when it comes to these larger aquariums, depth is also something to keep in mind. Aquarium lighting will need to be very powerful to reach the bottom of a very deep tank. While LED can provide excellent brightness, consider how many degrees of illumination each light fixture can give you and whether there will be any low-light corners in your tank after assembly. Deep tanks might require that the lights be hung low to the water surface- and that can also dictate which light you choose. Lights are often able to perch on the rim of tanks with brackets, but some are mounted from the ceiling to provide more adjustability. Depending on where you plan on keeping your tank, and how much space is available to you, this can be an important consideration.

LED Lighting for a 125/150 Gallon Saltwater Reef Tank

Finding a decent aquarium light for a fish-only saltwater tank is often not a problem. Fish and live rocks alone are pretty flexible when it comes to lighting, and therefore you can get away with pretty much any setup that gives you a good view and fits your budget. However, if you are trying to grow coral in a reef tank, lighting becomes an extremely important factor. Corals are extremely light-sensitive and need blue light in particular to survive and grow. Hard and soft corals will both need different light intensities, so this is also something to consider. For a larger tank, it can be beneficial to have several lights with varying intensities in order to accommodate each type of coral. Some even recommend using supplemental lights such as actinic bulbs to create more blue light to aid in coral growth. Blue light also tends to make the vibrant colors of tropical fish really ‘pop’.

1. WILLS 165W LED Full Spectrum Light

WILLS 165W LED Full Spectrum light fixtures are an extremely versatile and customizable option for reef tanks. The full spectrum light features fully adjustable white and blue light channels- excellent for fine-tuning to both hard and soft coral. Additionally, each light features two timer settings- one for the blue light channel and one for the white light channel- to further customize the light cycles for your reef. Here you can find the WILLS 165W LED Full Spectrum Lights.


  • Full-spectrum of light designed specifically for reef tanks
  • Fully adjustable white and blue light channels, with corresponding timers
  • Built-in fans and optimized heat sinks keep the lights cool


  • A pricier option, and at a smaller size requiring multiple lights for a large aquarium

Built-in fans and aluminum heat sinks to ensure that these lights will stay running cool. This light fixture is of a smaller size, with dimensions of 16x8x2 inches, and you will need 4 or more of them to provide full coverage for a 125 to 150-gallon aquarium. Though a pricer option, this product has a dedicated following and a 3-year warranty.

2. The Aquatic Life LED Aquarium Light Fixture

The Aquatic Life LED Aquarium Light Fixture is another great option for saltwater tanks. Although less customizable than the MarsAqua model, this light provides a full spectrum of light for reef tanks- including a sunrise and sunset option where the lights dim slowly between day and night. The 3-channel timer lets you designate time periods for the white, blue, and full-spectrum light channels. Here you can find the Aquatic Life LED Aquarium Light Fixtures.


  • Full-spectrum light designed for reef tanks
  • Sunrise and sunset options offer a natural light cycle to your tank
  • Optional WiFi capabilities enable remote light adjustments via the app


  • Light intensity is not adjustable

This light fixture comes in several models- including a WiFi option, which allows the timer and light configurations to be controlled on the go from a smartphone app. Another benefit of this light fixture is that it comes in a variety of sizes- with the largest clocking in at 48” long. Although you will still need multiple lights to cover a large tank, the large size will have it covered with fewer units.

Related Questions

What are alternatives to LED lights?

Although we have covered why LED lights are a great choice for aquariums, there are some folks, especially beginners, who are not ready for the investment. This can be challenging because many basic aquarium kits do not come with LED lights- so it can help to learn about the other kinds of lights available.

Incandescent lights are often similar to household bulbs and are not the greatest choice for aquarium use. These bulbs get hot quickly and often do not have a long lifespan. Fluorescent lights are the most common standard issue bulb that comes with an aquarium kit, and if you are not committed to using an LED light, a fluorescent light fixture is not a horrible option. If your aquarium kit came with lights built into the hood, it is likely that you have fluorescent lights. Metal halide lights are also a common aquarium light, especially in marine aquariums. This is because these lights also produce a full spectrum of light that is essential for plants to thrive. However, metal halide lights run very hot and often require a chiller to prevent your tank from overheating.

What is PAR?

PAR stands for Photosynthetically Active Radiation. PAR determines how much light, and what spectrum, is reaching a certain depth location of your aquarium to allow photosynthesis. Photosynthesis is key to the growth of plant matter and coral, so it is a measurement that can be instrumental in finding whether or not a light is going to work for your individual aquarium needs.

What are actinic bulbs?

Actinic bulbs emit light from the blue end of the spectrum and mimic light in deep water. It is heavy in ultraviolet wavelengths and is great for promoting photosynthesis in invertebrates such as coral. For this reason, actinic bulbs are often used as supplemental lighting for reef aquariums, where it can encourage corals to produce more vibrant pigments.

How do I prevent algae blooms?

One common concern with all aquarium lighting is fighting algae. Of course, the same light and photosynthesis process that causes aquarium plants to thrive can also encourage algae to form in your tank. While a little bit of algae is normal and a sign of a well-balanced tank, algae that are too well fed can grow out of control and take over many surfaces in the tank. If left unchecked, it will compete with resources that your aquarium plants feed on, leading to plant die-off. Making sure your aquarium lights are on a schedule is important to keep algae growth in check. This is why timers and 24-hour light cycles can come in handy. Aside from lighting control, algae can also be kept in check by making sure you are not slacking on water changes and aquarium cleaning. Many aquarium inhabitants, such as snails and shrimp, feed on algae and can help keep levels down to a manageable level.


As you can see, there are many different factors that come into play when deciding on the best-LED aquarium lighting for your tank. As with many aspects of fish keeping, your personal preference and expectations for your light fixture will determine the best choice for you. LED lights are the best choice for any aquarium in terms of performance and efficiency, and the level of control they give over the environment is unparalleled. It is likely that most of the adjustable LED lights would be suitable for any aquarium environment. In fact, some LED models are so adjustable that the number of options can be overwhelming- but the ease of changing them means that you are free to experiment with them often as you want without trouble.

The flexibility of these lights can seem even more complicated when outfitting a larger 125 to 150-gallon tank, but many of the light fixtures that we discussed are easy to scale up to a larger tank- and they do not all have to be programmed the same. Large planted tanks and reef tanks often call for a more nuanced and sophisticated light setup, to begin with, and having multiple customized lights are a great way to make sure that all inhabitants of your tank are thriving. You do not necessarily have to choose just one type of light for your entire aquarium, and there are plenty of do-it-yourself lighting projects that are perfect for large aquariums as well.

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Hi, my name is Jordan. I've been in the fishkeeping hobby since my childhood. Welcome to my blog where I help fishkeepers enjoy the hobby by offering free guides, advice, & product reviews. Read more...