@Iluviaporos - I would also suggest that people do a trail run for a while before they put any fish and especially any coral into their tank. Live rock and corals are expensive, and even plants for freshwater tanks can be expensive.
You want to run your fish tank water heater for a few days, testing the water in different places to make sure the temperature is even and holding steady at the range that you need.
A failed fish tank is expensive, and also very sad. Make sure you have backups for your heater as well. If the power goes out, how are you going to heat your fish tank? It depends on you to make sure you have the answer to that question.