“In this instructable I wanted to show you how to make the aquarium controller. There are many controllers available in the Internet, but they cost at least $100. My controller costed about $15. Another great thing about making your own aquarium controller is that you can personalize it. Alright, but why do I need it? Aquarium controller is a huge help for every aquarium owner. It can control leds (turn it slowly on and off at a given time), measure the water temperature (and turn on the alarm if the temperature is too low or too high), feed your fish, monitor the water level, check the pH of water, etc. It can control everything that you have to control in your aquarium and measure every parameter that is relevant for you, your fish and plants. OK, you know why you need it, now let’s see how to make it.”