Lighting Systems for Your Planted Aquarium

April 03, 2022 5 min read 0 Comments

One of the most important aspects of owning an aquarium is your planted aquarium lighting system. Nothing is more essential to the healthy growth of aquatic plants than proper lights. They are also an incredibly important factor to consider upfront when designing your tank and the space it will reside in.

Lights aren’t just needed for nutrition; they also serve an aesthetic purpose. A well desi-ned and elegantly lit aquarium is a beautiful addition to any room in your house. Having a proper lighting system will also make your aquatic plants come to life and look stunning. Some lights even have the ability to make the color of certain fish and plants more vibrant looking.

When deciding on how much light your aquarium will need, you’ll need to account for the types of plants you wish to grow (not all plants grow equally or require the same nutrition), how much time you can commit to maintaining your plants (some strains require more maintenance than others), whether or not you want to invest in a carbon dioxide system, and how quickly you want your plants to grow.

If you are new to the world of planted aquariums, we highly recommend you choose an aquarium that is built to handle low light. These lighting systems are much easier to install and maintain, plus the regular upkeep is minimal. The vast majority of aquatic plants will grow under low light conditions, some just may do it at a slower rate. A low-light system is also more affordable because you won’t need to install a carbon dioxide injection system. You will also avoid algae outbreaks since you won’t be causing any light nuisance while using a low-light system.

Let’s take a look at some of the other aspects to consider when building your aquarium’s lighting system.

Light Bulbs

Historically speaking, the most commonly used and best planted aquarium light has been fluorescent bulbs. The right fluorescent bulb is capable of growing hearty plants, even in densely planted tanks. However, recently LED lighting has become a lot more popular amongst aquarists. LED lights have a very low operating cost, last a long time (over 5 years), and offer incredible lighting effects.

Let’s look closer at all the available options for aquarium light bulbs.


  • Fluorescent Bulbs: As mentioned earlier, these are the most common traditional bulbs. They come in all shapes and sizes and it is fairly easy to find one that will fit most any tank out there.
  • Pros: Fluorescent bulbs are great for plant growth, readily available and more affordable than most other options.
  • Cons: They do not have the longest lifespan and often run hot.
  • Metal Halide Bulbs: Metal halide lights have a color temperature which duplicates that of natural sunlight. This makes it ideal for the freshwater aquarium or reef tanks.
  • Pros: These lights feel like they last forever; the lifespan is fantastic. They typically consume about the same energy as your average bulb and often feature a slim profile, for a sleeker and more space-saving feel. Light produced from a metal halide light also penetrates deeper into your water.
  • Cons: Unfortunately, these lights are more expensive, for high-end enthusiasts. Metal halide lights also run extremely hot, so be careful.
  • LED Bulbs: LED lights are fantastic. They are safe, affordable, use very little energy, come in a wide variety of colors, and they produce practically no heat. They are the bees-knees of aquarium lights and a great option for new and expert aquarists alike. These lights are incredibly efficient at helping plants grow. The light they produce penetrates deep and adds a nice glow to the whole aquarium.
  • Pros: LED bulbs require less energy, produce less heat, last a long time, offer natural shimmering and come in a variety of colors.
  • Cons: Some models can be expensive, but there also plenty of very affordable solutions to combat this.
  • Halogen Bulbs: These lights are the modified version of traditional bulbs. Halogen lights also work by transferring electrical current via tungsten wire. They are very powerful and can last for a long time if properly maintained.
  • Pros: Halogen bulbs are reasonably priced, readily available, long lasting and very powerful.
  • Cons: These bulbs produce a large amount of heat.


The Power of Your Lights

When choosing your aquarium’s lighting system, it is crucial to factor in your specific lighting needs. Take into account what plants you want to grow, as some require more light to survive and thrive than others. Also consider the size and depth of your tank, as tall tanks require stronger lights to reach the bottom of the tank where the roots of the plants are.

Using a higher lighting system increases nutrient demand in the form of fertilizers and carbon dioxide injection systems. If you don’t balance higher output lights with these elements you will expose your plants to too much light which could cause algae to grow.

*Pro Tip* If you decide on a lighting system that ends up being too intense for your plants, there is an easy trick to compensate. Simply raise your lighting rig higher above the surface of the water or disconnect/cover one or more of the light bulbs.

Lighting Cycles

For most aquariums, you won’t be leaving the lights on at all times. It is important to have your lights turn on and off at the appropriate times in order to ensure that your aquatic plants grow properly. This also helps to prevent algae outbreaks. Most systems are able to be put on a timer so that you can automate this process and provide a consistent amount of light to your plants every day.

The rule of thumb is to never leave your lights on for longer than eight to ten hours. Any longer and you’re opening the door and inviting in the algae. If you are developing a new tank, avoid leaving your lights on for longer than six hours at a time. The first few months of plant growth should be slow and stable to avoid algae. Your fish also depend on a lighting cycle to thrive. The lights turning on and off signals them when to rest and when to be active.

Light Spread

One of the more overlooked aspects of aquarium lighting is that of light spread. This refers to how deep the light will penetrate the water and how far it disperses. Any plants that are deeper than one foot are going to receive less nutrients than those that aren’t.

When building your tank, try to match the tank dimensions to your light system spread. You can also use reflectors to bounce the light to particularly shaded areas of your tank or places with dense plant growth. Most aquarium shop experts can help guide you to selecting the proper lights and accessories to match your aquarium’s dimensions.

Color Temperatures

Choosing the color and temperature of your light is a minor, yet important aspect of your lighting system. Quite frankly, the color you choose should be the one you find most appealing. While there is a range of light temperatures to choose from, most plants will grow under the majority of temperatures. Blue light is fine, but you want to avoid actinic bulbs for freshwater.

While most amateur aquarists will opt for a “daylight” temperature, around 6500 Kelvin (K), most plants aren’t picky about your choice. Aim to keep your light system between 6000K – 8000K. Try and choose a color that enhances the natural color of your plants, and if you can swing it, your fish too.

Which Light is Right for Your Aquarium?

Now that you are equipped with a broad understanding of what it takes to properly light a planted aquarium, it is time to decide which lighting system is right for you. If you’re new to the world of planted tanks, there’s nothing wrong with buying a cost-effective light that does well at growing low light plants. If you want to splurge and get some more expensive lights, they will last you longer and often have extra features that basic lights do not.