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DIY LED Aquarium Lights: A Planted Aquarium Lighting Guide

About DIY LED Aquarium Lights,Besides providing housing for your aquatic pets, fish tanks and aquariums can be excellent decorative tools for your home. Besides providing housing for your aquatic pets, fish tanks and aquariums can be excellent decorative tools for your home. An amply lighted mini aquarium can give a room a visual mystique or calm.

Generally, most fish tanks’ biggest issue is their price tag, especially if you add lights to the equation. In contrast, you can save some money by adding your lighting. All you need is a bit of skill and knowledge.

Once again, your friends at WellPCB have got you covered. This guide will show you how to add DIY aquarium and reef lights to your fish tank.

How to Make DIY LED Aquarium Lights

What Are LED Aquarium Lights? 

Whether you plan to customize a freshwater or saltwater aquarium, adding lighting can add something truly special to your setup. While the main purpose for aquarium lighting is more decorative than it is pragmatic, it can still help you feed your pets in the dark. If you have nocturnal fish, it can provide them with a bit of lighting. Additionally, there is something meditative about gazing at your fish or plants in a dim room. 

Some worry that aquarium lights may be bad for fish. Certainly, they are not. Lighting options include incandescent (using incandescent bulbs), standard fluorescent, compact fluorescent, T-5 HO, VHO metal halide, and LED.

Compared to the other options, LED lights are small, energy-efficient, and the best option for freshwater tanks. As you will discover in the rest of this guide, they are also quite easy to use. 

Materials and Tools

Before you can start building your own custom LED aquarium lights, you will need the materials and tools to do so.

  • QT Py microcontroller x 1
  • Adafruit NeoPixel LED dots strand – 20 LEDs at 2″ pitch x 1
  • 2-pin connector x 1 
  • 3-pin connector x 1
  • Adafruit NeoPixel Digital RGBW LED strip – black PCB 144 LED/m x 1
  • Extension wire ribbon cable x 1
  • Clear heat shrinks
  • Copper tape x 1
  • On/Off Switch x 1
  • USB C Cable x 1
  • Solder-seal wire connectors
  • Hammer
  • ¾” cable staples
  • Heat gun
  • Soldering iron with solder
  • Hot glue gun

Besides the above tools and materials, you will need aquarium accessories such as aquarium gravel, colored glass, plants, and seashells. These are not compulsory; they are just lovely to have. However, to follow these steps, you’ll also need a basic understanding of the soldering process

How do you make an LED light for an aquarium?

Now that you have all your materials and tools, you can begin constructing your very own DIY aquarium led lights using the following steps: 

Step 1 

Install the necessary software and load it onto the QT Py microcontroller. You will need to install the latest Arduino IDE, Adafruit Board Support for QT Py, and a few critical Arduino libraries, including FastLED, Adafruit_FreeTouch and, Adafruit_NeoPixel.

Setting up Arduino’s software should be easy, but you can follow their installation guide to minimize any issues. 

Next, you need to set your QT Py board up. For instructions on how to do so, follow Adafruit’s QT Py Arduino IDE tutorial.

To install the libraries, you will need the Arduino Library Manager. You can read about installing additional Arduino libraries from Arduino’s official website for more details on this. Essentially, you need to select ‘Include Library’ from the ‘Sketch’ menu and then select ‘Manage Libraries.’

Finally, you can then search for libraries by name. Once you find a library, click on install. Find and install the FastLED, Adafruit_FreeTouch, and Adafruit_NeoPixel Libraries. 

Step 2

Download the Neopixel Aquarium code. Next, connect the QT Py microcontroller to your computer using a USB cable. Open the code file using the Arduino IDE (select ‘Open’ from the File menu). 

Next, click on the ‘Tools’ menu, select ‘Boards,’ and then click on the Adafruit QT Py option. Again, select the Adafruit QT Py microcontroller from the ‘Port’ menu item under Tools.       

Step 3 

In this section, you’ll wire your microcontroller to the Neopixel RGB LED strip. First, connect A1 to DIN, 5v to +5v, and G to G. Finally, you’ll need to run a lengthy wire from the microcontroller’s A2 and A3 for the on and off switch. 

After you complete this step, it should look like this diagram

Step 4

Connect the 3-pin connector to the microcontroller. Start by soldering the left wire connects to G, the right wire to 5v, then the middle wire to A1.

Next, connect your 2-pin connector to the microcontroller. You should solder it to the A2 and A3 pins. 

Once that’s done, take the red, black, and white wires from the Neopixel strip and solder them to the 3-pin connector’s male side. The white wire connects to A1, black to G and red to 5v.

Take two long single wires and solder each to a pin of the male 2-pin connector. They must be sufficiently long to extend to your copper switch pads. Finally, connect your microcontroller to the 2-pin connector.

Step 5

You will need to waterproof the setup by sealing both ends of the Neopixel strand using the heat shrinks. Additionally, you can use solder seal connectors with silicone-stranded wire to waterproof your underwater connections. 

Once you waterproof all the conductible components, you can hook the entire set up to your aquarium using wire staples. Importantly, your microcontroller powers your lights, but it needs to connect to a USB power source to do so.

DIY Aquarium Light Kit

Using the above steps, you should create and test your DIY LED aquarium light kit. Whether you implement it in the aquarium’s lid or run it through the reefs and rocks of the aquarium floor is up to you. Thus, you have a bit of flexibility in following the steps and using the aquarium lights. 

How to DIY Change Color LED Aquarium Lights

Depending on what type of light strip you use, you can manually change the colors in several ways. For instance, the NeoPixel LED dots strand allows you to change colors by squeezing the non-wired ends or by connecting a switch or touchpad to do so. However, if you want to switch between colors automatically, the best way, as evidenced by this guide, is to use a microcontroller.

Why Are the DIY LED Aquarium Lights Not Working?

You need to ensure that you plug in and solder all necessary connectors. If you are running your DIY LED lights using a microcontroller, ensure that your code is uploaded and running correctly on the board. Furthermore, make sure that your LED light strip is not faulty. 


Are LED lights good for aquariums??

LED lights are harmless and will not affect plants or fish in an aquarium. However, they can help you see your aquatic pets better and help you regulate their sleep patterns.

How many LED bulbs are best for a planted aquarium?

It depends on the size of the aquarium. Typically, people use between 1.5 and 5.0 watts of lighting for every 3 liters of aquarium space. 

What is the best light spectrum for aquarium plants?

The best light spectrum for aquarium plants includes at least 50% of red light in the wavelength of 630 to 700 nm. Additionally, 35% green light in the wavelength range of 500 to 580 nm; Finally, 15% blue light in the wavelength range of 435 to 495.

Can I use any LED light for a fish tank?

Yes, you can safely use almost any LED light for your fish tank as long as it has waterproofing.

Do LED aquarium lights cause algae?

LED aquarium lights do not cause or encourage the growth of algae. The truth is that too much light from any light source may cause algae to grow. You should only leave your aquarium lights on for eight to twelve hours per day. 


A well-lit aquarium is a great way to give your home a unique glow and distinct look. Essentially, it is a dynamic decoration. You do not have to hire a specialist or buy an official aquarium LED kit. You can simply follow the instructions highlighted in this guide. We show you a few simple steps on how you can build a DIY LED aquarium lid and reef lights in them. We hope that you have found this guide to be helpful. If you have any LED or PCB related questions, please contact us. As always, thank you for reading.

Hi, I am Hommer, the founder of WellPCB. So far we have more than 4,000 customers worldwide. Any questions you can feel free to contact me. Thanks in advance.