Introduction: Easy and Cheap Aquarium Moonlights

About: I like building things that are cheaper then you can find in stores and can modify to suit your needs. Let's face it companies build for the masses, I build for me! Anything IoT, Reef Keeping and Aquaponics a…

My 90 gal reef tank has 2 150 watt led fixtures, but being from different manufacturers one doesn't have a moonlight function. I am happy with the light fixtures themselves so instead of buying something new I decided to add moonlighting myself.

NOTE: I assume you have an aquarium, adjust the specs for your aquarium size. My 90 gal is 48" x 18" X 24"

Step 1: ​WARNING!!!


This project involves wiring in close proximity to water. Use caution including following directions carefully and general safety practices. Safe assembly and operation of this project is the user’s responsibility. Do not make changes to the system while the device is plugged in.

Step 2: Parts Needed

You will need the following parts:

1 - 1.37 m (4 1/2 ft) 1x2 stud lumber (Home Depot -1.10$ for 8 ft)

1 - DC power supply ( 5 VDC and 2 Amps is ideal for my led's, but check the specs of your led's)

Adhesive - I used clear tape as I found the tape on the back of the led's and double sided tape not hold very well and the fact that the led's are suspended over water made this an important decision.

1 - 1 m (3 ft) LED string
The type of led doesn't matter, you can get just blue or a multicolored version, There is also a water resistant version but it costs a lot more, they are all over ebay usually about 10$ for 15 ft

Step 3: Assembly

First you want to make sure that your 1x2 lumber will fit the top of your aquarium or your canopy safely. You also want to make sure you have a safe spot for your power supply. My lumber is 4 1/2 ft, so I have it hanging over the side of the tank with about 4" clearance for the power supply, I also covered the power supply with cellophane to protect from any water that may happen to splash out of the tank. Over heating hasn't been a problem yet, but it is possible.

Next lay your lumber on the ground and lay your LED string on top of it to make sure it covers most of the tank. Leaving a couple of ince's on both sides is desirable.

You can attach the LED string to the lumber anyway you like, but I found that running the tape in loops over the LED's and the lumber to be the most secure.

Step 4: You're Done!

Finally decide where on the top of the tank you want to have the light's I found the middle slightly back to giv ehte best results.

Voila, you now have moonlights on your aquarium for under 20$ and likely no more than 30 min to assemble.. It's a simple and cheap project but add's a great view and gives a more natural environment for your livestock.