Introduction: Automatic Light and Pump Aquarium System With Arduino and RTC Timer

About: VOIP and media stream engineer , robot hobbyist, clean energy supporter

An aquarium can be made into a zero intervention required self sustaining ecosystem with some care and tech :)

To build Automatic Light and Pump system for an aquarium , of-course setup a manual system first .

I used 2 flood lights 50 W each and 1 6W 400 L/h cannister filter for a 2.5 m x 1 m x 1.5 m tank .

Although Arduino is capable of maintaining timer by itself , it will reset itself every-time electricity supply restarts which could lead to over feeding in the aquarium , hence an external RTC timer with its own separate power supply is ideal to maintain time for arduino device and associated system.

As a modification to automatic system , I have also added a manual override button which enables to me override automatic state and turn the light-pump system on or off manually anytime i want to. It does not affect the timer in any way and timer based system works smoothly as it is when manual over-ride is turned off .


  • Gesto Metal 50 Watt 220-240V Waterproof Landscape IP65 Perfect Power LED Flood Light (White) x 2
  • daisye88 External Canister Filter 6W 400 L/h Filtration System
  • Arduino UNO
  • DC adapter for Arduino
  • RTC Timer + coin cell
  • 2 pair male female plugs
  • Switch button
  • Empty mobile box
  • wires

Step 1: ​Assemble the Components

Use the Circuit diagram given to attach external power

Step 2: Add Manual Override Switch and Box Up the Assembly

Fit the assembly in a small size box such as old phone case .

Add a manual override switch button

Cut groves on the box for the wires to pass and reattach plug from outside as shows in image

Step 3: Video Before Box Assembly and After

Timings for Automatic lights and filter to switch on

  • 7 am - 9:59 am
  • 7 pm - 9:59 pm

Total 3+3 =6 hours a day