I am almost at the point of not having major problems. Almost, but not quite. In the 46 years my reef has been running the tank never actually crashed but I have had many floods. Too many to remember but thankfully they are much less frequent now because every time I had one, I designed a better system. In the construction industry we had to build what was called "Fail Safe" which means, if that part fails, Nothing would happen. Like electric locks, they are fail safe so if they fail, or if there is no power, the doors will open. That was problematic when I wired the jail cells for the "Dangerous Drug Division of the FBI" because when the lights in the street came on, there was a voltage drop on the street, all the locks would reverse and the offices would lock, but the jail cells would open. I found that out before they had any prisoners in there.
If the power goes out in my tank, nothing happens except the pumps go off. I don't have a sump, so no problems with that flooding. I have had small plumbing leaks in my DIY, 5' skimmer which caused a flood but now there is a five gallon bucket under it with a DIY shut off switch that turns off the pump feeding the skimmer if the bucket fills, which happens all the time.
My DIY, water cooled LEDs are on two separate systems so one can fail but half the lights will still work. Also if the water cooled pump for the LEDs fail, the lights go off to prevent them overheating.
I also use 3 heaters so if two fail, one still works and 4 powerheads.
There is also a water alarm under my tank that warns me of a leak.
In those years the power has gone out numerous times for days at a time. I think I was out 4 or 5 days during Sandy. I use a reverse Undergravel filter and power outages do not affect it at all. The power could stay out forever.
Now I have a generator but during Sandy, I ran out of gas here on Long Island even thought I siphoned it out of my cars and boat. I now made it so that my generator runs on gasoline and natural gas so I can run it forever.
I keep my fish immune so they never get diseases and I have no need of a quarantine or hospital tank so no worries there.
Now if I could keep my fish from jumping out, I would have it made.
