Aquarium Controller

This Instructable will show you how to make a Aquarium Controller. First of all: I’m not an engineer and I’m not a programmer. There may be errors, so please ask if there are any ambiguities. We do not want to make a fishcooker :) I hope you have some fun und enjoy this project. Ok, now some background: I have 4 aquariums and needed a lot of time switches for the light, because I use daylight, zwilight, nightlight or spotlight. Than I need time switches for CO2-solenoid valves (CO2-switches?) and some sockets for some heater. A lot switches, a lot sockets, a lot of money you need. It would be much easier if an Arduino could do that all. I thought a little: I do not want high voltage on my controller, because I’m not a professional. I want all in one and I want to see how it works. That´s all ;)”