Choosing LED lights for 125 gallon aquarium is a little challenging given the dimensions a larger tank has. You need lights that are both long enough to cover the distance as well as powerful enough to penetrate the depths.
This need for strong illumination is doubly important when keeping live aquarium plants and corals, both of which are photosynthetic and require good lighting. Fish are less picky when it comes to light.
But quality full-spectrum lights will still maximize your viewing pleasure and are a worthy investment. So what should you understand about shopping for LED lights for large tanks?
Table of Contents
- Why Use LEDs As Aquarium Lighting Options?
- Choosing An Aquarium LED Light Fixture
- Lighting A 125 Gallon Freshwater Aquarium
- Lighting A 125 Gallon Planted Tank
- LED Lights For 125 Gallon Aquarium Saltwater Reef Tank
- Frequently Asked Questions About LED Lights
- In Summary
Why Use LEDs As Aquarium Lighting Options?
Over the past decade, LED lights have undergone a tremendous shift in popularity within the aquarium hobby! Years ago, they were considered some of the most expensive specially designed lights you could buy.
However, manufacturing in Asia has brought prices down considerably. And considering all of the benefits LED lights have over fluorescent lights, they are the better buy for nearly all fish tank setups.
Fluorescent lights were the first step of improvement beyond incandescent light bulbs. Incandescent light bulbs have a very warm output that’s cozy for home interiors but poor for coral and plant growth.
They also emit a lot of heat, not as much as metal halide lights but enough to be a worry, especially for smaller aquariums.
Fluorescent lights still create heat, enough that they can crack if suddenly splashed by water from a filter or during a water change. LED aquarium lighting is the modern solution to keeping a fish tank well-lit. They run very cool and emit little dangerous heat.
The spectrum of light that an LED aquarium light emits can also be easily tailored to meet the needs of an aquarist. If you need full-spectrum light for the day but additional blue light during the evening, it is easy to include the requisite bulbs within the fixture.
The best LED lighting is also incredibly long-lasting, up to 50,000 hours (5 to 6 years of daily use) of output in many cases.
And despite their longevity, these bulbs are also extremely energy-efficient, using 50-80% less energy than a fluorescent or incandescent light fixture.
Choosing An Aquarium LED Light Fixture
With all of the options available in today’s online marketplace, we are really spoiled for choices. There are few truly bad brands out there and a heck of a lot of good.
That said, if you are reading this article, you likely want to know how to pick out a quality aquarium lighting brand and product. So here are some aspects to consider when choosing aquarium LED lights.
Full Spectrum Aquarium Lights
Full-spectrum lighting is important in order to grow coral in a saltwater fish tank as well as caring for live plants in a freshwater fish tank. Both of these organisms are photosynthetic, meaning they use light to produce food for themselves. But not all light is created equally.
For the most part, we need to look at aquarium light fixtures that emit the same colors that natural sunlight does. This range is called photosynthetically active radiation (PAR), and it varies depending on the organisms in question.
For example, you can have strong coral growth even with light that is shifted far into the blue-purple range using actinic light fixtures. This is an adaptation by corals since they have to make use of the abundant blue wavelengths found in the ocean.
But freshwater aquatic plants are far more photosynthetically active in the longer wavelengths (blue, green, yellow, orange, red).
Light Intensity Control
Another useful feature to be on the lookout for is a mechanism to control the intensity of the LED lights. Variable light output is very useful because sometimes you won’t want full power from your light fixtures.
Maybe you are having algae issues in your freshwater tanks and want to dial the light output back for a week without seriously harming your plants. If so, then being able to set the aquarium lights to 75% power can be very helpful.
Likewise, if you see signs of stress in a newly moved coral and want to give it time to acclimate.
Integrated Light Timers
Most LED aquarium lights are somewhat to entirely compatible with timers that are sold separately. They typically fit in between the power source and cord and can be programmed to shut on and off in a simplistic fashion. But integrated light timers are very handy because they offer a wider range of options.
Since they are fully compatible with the unit, they are attached – or built in – to, you can program more subtle changes to the light levels. You can time overcast days, thunderstorms, sunrises, sunsets, and other gradual shifts.
These changes not only increase viewing pleasure but also provide natural chronological shifts for the life cycles of plants and corals.
One aspect to buying LED and fluorescent lamps that are sometimes forgotten is the angle of light coverage that the fixture provides.
This is less important in a fish tank free of corals or plants. But good plant and coral growth depend on all of your sessile (non-moving) aquarium inhabitants having access to bright white light with photosynthetically active radiation (PAR).
And in a heavily planted tank or well-stocked reef tank, some spots might not be getting as much light as the middle of the tank directly under the fixture does.
The corners and edges can lose as much as half the rated light output if the aquarium light is too small or not built to maximize the spread.
The height of the aquarium lights also matters a lot. This makes lighting a 150-gallon tank even more challenging because of the extra 7 inches of height relative to a 125-gallon tank.
The extra height means that even if you choose a fixture that covers the bottom area of a 125-gallon tank, it will be less intense than expected since it is further away from the substrate.
Additional Features For Light Fixtures
Lastly, when shopping for a new LED light fixture, be aware of any additional features that are included or are especially important to you. For example, some models are water-resistant and have an IP rating to reflect this.
Believe it or not, water and splash resistance is actually not so common in aquarium light fixtures! So a unit that offers it is providing an extra bit of security that may leave you more willing to place it above a cover-less fish tank.
Other additional features can include longer-running LED bulbs, more energy efficiency, a wider suite of color options, or lighting effects like weather, overcast, or moonlight.
Lighting A 125 Gallon Freshwater Aquarium
Now that we have a good grasp of what is important in a quality product, here is our top pick for the best LED aquarium light fixtures for 125-gallon fish-only tanks!
Since fish don’t eat light (unlike plants and corals), the intensity and spectrum aren’t quite as important. However, we still want powerful light to bring out vibrant colors in our pets. And enough illumination to light up all parts of the fish tank.
1. NICREW ClassicLED Plus Planted Aquarium Light
As mentioned before, aquarium lights have become much more affordable over the years without sacrificing quality. And the NICREW ClassicLED Plus line is one of the best examples of this trend.
Here we have a high quality, durable, and long-lasting lighting solution with vibrant colors that only costs a fraction compared to the competition. You don’t get the built-in timers, weather controls, and a suite of custom light color temperature options.
Instead, you have either standard daylight or blue moonlight. NICREW also offers full intensity control ranging from 0 to 100% output, ideal if you want to keep nuisance algae under control.
What’s more, this unit is still usable for freshwater plants. At 100% intensity, the NICREW ClassicLED Plus is rated as suitable for low to medium light plants, though in a shallower aquarium, you could grow high light plants.
Though the lack of added features makes it not as good for the planted tank compared to the options outlined below.
Also, be aware that the ClassicLED Plus has a maximum length of 54 inches, so you will need more than one to fully illuminate your tank for medium-light plants.
- Very affordable light option for fish tank LED lighting
- Simple controls and fewer overwhelming options
- No weather or additional color options to choose from
- No built-in timer (but is compatible with timer units sold separately)
- Feature set not ideal for a planted aquarium
Lighting A 125 Gallon Planted Tank
125 and 150-gallon planted aquariums have slightly different needs from fish-only tanks.
For starters, both the light intensity and spectrum are much more important.
Without both in the right levels, your plants are less likely to do well. Fortunately, each of the options detailed below is more than suitable for medium to high light plants in large aquariums!
2. Current USA Satellite Freshwater LED Plus Light
Thanks to the full spectrum light output and minimalist design elements, the Current USA Satellite is a good option for discerning aquarists. Remote controls are standard for LED lights these days, but few offer 32 buttons worth of control!
You have access to dynamic weather settings like cloud cover, fading moonlight, thunderstorms, dusk, and other complex light environments. The unit also casts light in a way that creates a shimmer effect similar to how natural sunlight and metal halide lights look above a reef tank!
The only real downside is that the mixture of white and blue LED lights is optimized for viewing purposes. The Current USA Satellite absolutely will grow coral and plants, but the cooler color is not optimal for live plants.
The warmer 660 nm true red bulbs of the Finnex Planted+ are more efficient at stimulating plant photosynthesis and improving the overall look of a planted tank. Current USA rates the Satellite as ideal for low to medium light plants.
- White/blue LEDs are ideal for fish viewing
- Shimmer effect similar to reef tank lighting
- Ability to create settings for overcast conditions, thunderstorms, and other weather
- Largest unit covers 60 inches in length, making it suitable for a 125-gallon tank
- Light output is rated up to medium-light plants only
3. Finnex Planted+ 24/7 ALC Aquarium LED Light
Finnex is another brand that’s well known for making quality light fixture options. Finnex actually has a few lights designed specifically for the planted tank, including their HLC and Planted +Original lights.
All are excellent for growing aquarium plants, but the ALC is one of the lines that include the Finnex 660nm true red LED bulbs.
Coupled with full-spectrum light, these bulbs ensure that the Planted+ ALC outputs an ideal spectrum of light for plant photosynthesis.
The slightly warmer look is also perfect for the vibrant green and reds of freshwater aquatic planted tanks.
Each ALC light fixture also has the highest light intensity of any of the Finnex models, making them ideal for medium to high light planted aquariums. For a 125-gallon tank, the PAR rating will be 80-90 at substrate level directly under the fixture.
Just be aware that you will need two if you want full intensity across a larger tank. After all, the longest aquarium light Finnex makes is 48 inches long (a 125-gallon tank is 72 inches long).
- 660 nm True Red LED bulbs for optimal plant growth and viewing
- Remote control for light intensity, output, and weather control
- Ultra-slim design to avoid taking up additional visual real estate
- 48″ is the longest available light fixture, meaning that two are required for full coverage of a 125/150-gallon aquarium
4. Fluval Plant 3.0 LED Planted Aquarium Lighting
Fluval is another famous brand in the world of pet products, and they happen to make some of the finest LED aquarium lights around! Their Plant 3.0 is especially unique because you have the option of buying one of three different power levels ranging from 32W to 59W of power consumption.
Thanks to its IP67 water resistance rating, the Fluval Plant 3.0 can sit right near the water surface on uncovered aquariums without any fear of damage being done to the lighting.
This is the approach favored by professional planted tank keepers since even a cover can diffuse and reduce some of the incoming light over time.
Each unit has a 24-hour programming cycle, so you can set and forget the light fixture from the very beginning.
Fluval also includes three preprogrammed “habitats” balanced around natural light viewing: the Lake Malawi, Tropical River, and Planted tank lighting options!
The mounting brackets on the side of the LED aquarium lights are capable of spanning up to 60 inches of space, so you may want two for the full span of large tanks like 125 gallons or more.
- Low, medium, and high power options to choose from
- IP67 water resistance
- Light cycle settings (including sunrise, sunset, and midday)
- Preset habitat-based light configurations
- No weather effects like cloudy days or thunderstorms
- Pricier than the other full-spectrum light choices
LED Lights For 125 Gallon Aquarium Saltwater Reef Tank
Of all the aquarium light fixture options out there, choosing setups for saltwater fish and coral reef tanks is the most challenging. These systems demand powerful light output at a very precise spectrum to keep corals and other sensitive invertebrates alive.
From all of the different models out there, here are the three that will meet the needs of nearly every marine reef aquarist out there!
5. Phlizon 165W Dimmable Full Spectrum Aquarium LED
Choosing the right light for hard and soft corals can be a challenge sometimes. Fortunately, as the Phlizon 165W demonstrates, it does not need to be expensive.
Phlizon actually makes two slightly different lighting options: a 16″ x 8″ and a 20″ x 7″ design. Both have the same number of bulbs and a 165W power output. But a longer unit is often preferred by reef tank enthusiasts with a larger tank, such as a 125-gallon setup.
You will still need more than one Phlizon to cover the length of large tanks, but it is a little easier with the extra 4 inches provided by the 20″ x 7″ model!
The design is straightforward yet modern. Control knobs on the sides power on the unit and modify light intensity. Fans help keep the unit cool since it is consuming much more power compared to any freshwater aquarium light.
And the spectrum of colors is tailored to meet the needs of coral growth without sacrificing in the looks department. The green and red bulbs give you a look closer to white sunlight, yet the UV and blue light also help accentuate coral colors in a way similar to actinic bulbs.
Just be aware that each LED aquarium light is meant to be attached from the ceiling and hangs down over the reef tank. They don’t sit directly on the tank like a traditional light fixture.
- Extremely affordable high, intensity lighting
- Ideal spectrum for both coral growth and viewing
- Straightforward controls
- Few additional features
- Multiple fixtures needed for large tanks
- Requires ceiling mounting
6. VIPARSPECTRA Timer Control Dimmable 165W 300W LED Aquarium Light
We love the VIPARSPECTRA lights for large tanks because it takes everything great about the Phlizon and adds to it. For starters, you have the option of both 165W and an even more powerful 300W fixture for high light organisms like Acropora and other small polyp stony corals.
VIPARSPECTRA also includes both a remote control and a timer built into their lights. You have two channels to modify with start and stop times for the lights as well as brightness controls. All of which can be controlled from both the unit as well as the included remote control.
You are paying more for the VIPARSPECTRA relative to the Phlizon, but you are also getting a higher quality unit backed by a 1-year local warranty. VIPARSPECTRA provides precise data, rating their units as having up to 100,000 hours of runtime, which is exceptional for even LED lighting options!
And in the long run, using the VIPARSPECTRA is on par with cheaper units. They offer a spread of 30 inches when raised 12 inches from the water surface. Therefore two that are properly mounted from the ceiling will cover the majority of a 125/150-gallon aquarium!
- 165W-300W options make them the best high-intensity lights for coral growth
- Includes a remote control and built-in timer
- 100,000 hours of runtime and a 1-year local warranty
- Pricier compared to other hanging LED lights
- Requires ceiling mounting
7. Current USA Orbit Marine LED Aquarium Light
You can easily program a 24-hour day/night cycle, complete with a natural dawn and a blue shift as sundown approaches. There are other programmable options as well, including dynamic weather effects like rolling clouds!
Unlike their Satellite freshwater version, the Orbit Marine LED includes a high number of actinic bulbs. Actinic lighting is popular for reef aquariums because they bring out more vibrant colors in corals and sea anemones.
The integrated timer and remote control included are also some of the more spectacular designs out there. Because it not only allows you to control light intensity, color temperature, and output.
The setup also integrates with the Current USA Wave Pump, allowing you to shape water flow and illumination all from a single remote.
For instance, you might set up the lighting to output maximum illumination, and for the currents to drop off for a few minutes of the day during each feeding period, so fish find every scrap with minimal fuss.
And at 60 inches in total length, it is one of the longer fixtures on the market. You may want to buy two of the shorter units instead to fully bridge the length of a 125-gallon tank – or aquascape the setup, so all of your high light corals are right under the fixture.
- Entirely customizable in terms of light output and intensity
- More actinic blue light for beautiful coral colors
- Controls link with Current USA’s Wave Pump
- One of the longest light fixtures available
- Fewer dynamic weather effects compared to other brands
Frequently Asked Questions About LED Lights
Now that we’ve explored some of the best LED lighting options for 125 and 150-gallon aquariums let’s answer some frequently asked questions on LED lighting!
What is PAR Output?
When shopping for lights that replicate the natural environment for soft corals and plants, we need to be concerned about photosynthetically active radiation (PAR).
Because no matter how bright your light fixture is, it may not be doing much good if corals, live rock, and plants can’t use any of its output.
PAR peaks in the blue to red parts of the visible light spectrum. PAR meters are available for you to measure the intensity of light under a light. But it is becoming more common for high-quality LED full spectrum light brands to list the exact PAR rating on the package for your convenience.
If you are growing low light plants and corals, then it’s not so important to know the PAR rating as long as you know you are getting full-spectrum light. But if you are setting up medium to high light reef tanks and planted tanks, then having high PAR levels is crucial to success!
Knowing what PAR levels plants and corals were grown under can also help ease their transition into their new homes. Distributors can list the light intensity they keep their reef tanks under in PAR units.
This way, you can match that intensity when your new additions arrive and gradually increase or decrease it over time. Adding corals or plants to powerfully lit setups when they were grown in lower light levels can be very harmful if done too quickly, even causing burns to sensitive tissues.
How Can I Prevent Algae Growth?
Algae is a fact of life in any aquatic system. Whether you have planted tanks, reef aquariums, or some other environment, you will need to know how to manage the algae that inevitably arise.
Algae needs two things to grow: light and nutrients. It is almost always present in some form because algae are (usually) microscopic cells and need very little compared to true aquatic plants. Even light levels that would kill true plants can still nurture algae.
But if you have loads of nutrients, such as fish waste, nitrate, ammonia, and leftover food, plus high intensity light fixtures, you are pretty much guaranteed to have algae growing in excess. So how can we prevent algae growth from taking over our tropical fish tanks?
If you have aquarium plants, then you need to encourage their growth in a way that helps them better compete with algae. Setting your lights to a timer allows them to synchronize their biological cycles to make the best use of available light.
Providing fertilizers on a regular basis also helps plant growth stabilize.
Remember, algae is a sign that growing plants aren’t making maximal use out of the available light and nutrients. Which algae will always be able to do better if the environment is always changing.
If you have a saltwater reef tank, introducing a little competition can also help get algae under control. Specifically, marine macroalgae, which look a lot like freshwater plants that come in fabulously bright shades of red, green, and pink!
Marine macroalgae aren’t usually as hard to get rid of as filamentous and green water algae. They also make an excellent food source for vegetarian pets like tangs, angelfish, hermit crabs, and nudibranchs.
As they grow, macroalgae soak up ammonia, nitrates, phosphates, and other sources of “pollution’ that can cause stress to fish and corals.
You can then either export them out of the system by simply trimming them back and throwing away the waste. Or feeding it to fish in another tank. Or simply allow the macroalgae to grow further, keeping these nutrients locked away in their leafy fronds.
What Color LED Light Is Best For Fish?
When shopping for aquarium lighting, you will quickly realize that there is a massive amount of options available when it comes to color output. We’ve already discussed the importance of full-spectrum light fixtures.
However, you also can find moonlight blue LEDs, purple, red, yellow, and any other color.
It is worth remembering that all of these extra LED lighting options are essentially for show. Natural light is yellow to white in color and is best for fish because it allows them to see more easily.
Some manufacturers suggest leaving on blue LEDs at night to simulate “moonlight.” But fish need to sleep, and the darker the tank is, the better.
Leaving on only blue LEDs can disrupt their sleep patterns just like it would do to you if you have to sleep in a room full of blue light.
So, in general, having different color LED lights is nice. But stick to yellow or white light as your main color for natural fish hues and activity!
Do I Need Strong Lighting For Low Light Plants?
Low light plants are a great choice for planted tanks because you can get away with LED lights with lower output. These plants require less energy usage because they typically grow very slowly compared to high-light live plants.
Low light plants also do well if you don’t plan on using carbon dioxide or intensive fertilizer regimens.
Some good low-light plants to choose from include java fern, anubias, java moss, and cryptocoryne species. All of these plants can be grown in high light environments, but they won’t grow much faster than they would in a low light tank.
A low-light planted tank also has the advantage of being easier to manage. Algae is fond of the high light and nutrient levels found in a traditional planted tank.
If you aren’t an expert in choosing the right plants and maintaining stable conditions, you might find it to be a frustrating and expensive experience.
That said, you do still need to choose specific lighting with the right spectrum. Even low-light plants need good PAR output and won’t grow using basic aquarium lighting.
Aquarium LED lights have a staggering array of features that can complicate the buying process. From water resistance and specialized red wavelengths to weather and intensity controls, the sky really is the limit here.
But hopefully, in this breakdown, you’ve discovered what truly matters for your particular large tank setup. And feel empowered to make precisely the right choice for your fish, plants, or corals!