LOL of course I know electronics fail. I have been designing electronic devices for 35 years!
I built my system with failure in mind and have constantly upgraded the redundancy when something unexpected happens. I have redundancy on every important part of the system and I don't just rely on email alerts when something goes out of whack. I also have an SMS module on my controller with it's own battery backup that will alert me via text message of a problem, even if the power dies.
My electronics are in a completely sealed cabinet away from anything involving water and as I said I have had just about zero failures. The only thing that I have had die is one temp probe which lasted about 13 years. I have two in my system and if any one of them reads outside the hysteresis point I get alerted. Also my controller is set to the outside range of my temp and the inner range is controlled by an Aqua Logic Nema 4x. I have never had a failure of my controller or power bars and that is because the design of the hardware and software is rock solid. I have looked at the circuit board in great detail and that's how I know the hardware design is solid. My opinion of the software is based on using it for so many years and not finding a single fault in it's core functionality.
It's ironic that you mention aircraft since the guy who designed all of Aquatronica's products was a lead designer for a company in Italy that made control modules for fuel systems in Aircraft and Cars. At some point around 2003 they decided to make a control system for Aquaculture and he was given the task since he was also avidly into SW aquariums as a hobby. He later got frustrated when they would not let him create more modules for the system so he offered to buy out that division of the company along with a few other employees. They then expanded the product line and continued the business from their own building.
BTW If you had any doubts about how seriously I take redundancy, you should know that I have a complete brand new Deluxe ACQ 140 system in my closet, still in the box. I also bought duplicate modules for everything not in that box. Even the expensive SMS module and spare dosing pumps.
I am always weary that some part may fail so I like to have every spare part on hand.