You have a perfectly created environment for your fish and plants that depend on electricity and mechanical equipment to maintain them. Mechanical equipment and or electricity will fail at times. That is why it is always good to have a plan B.
Make sure you had a licenced electrician check to see that all is up to code and you are not overloading the electrical system in the facility. Have back up heaters and chillers in case one of yours fails. Then you have a window to repair the equipment before the temperature is critical in your tanks. Have a generator on the property with a few days fuel to bridge the gap while power is restored. If you are worried about the water getting too hot and have no back up kill the lights for as long as you can. Usually, the benefit of the lights is not as important as the water getting too warm for some species. You know your situation better than me here. Maybe consider a solar or battery powered fountain to help evaporate the water to cool the tank or pond. Maybe a battery powered air pump to get some oxygen in the water too? You don’t want to have set up a bicycle connected to a coconut pump like Gilligan from Gilligan’s Island might do. 🙂 Maybe oversize your filters to give a little extra time when the system goes down? Put battery-powered monitors to alert you if there are any issues. The faster you know about a problem the faster you can work to resolve it.
I am on your side. I want happy healthy fish and little creatures out there.