I think that a good place to start (when bullet-proofing your tank setup) is to look at every component and consider the possibilities if (and when) that component fails. Start with the components with the biggest potential for disaster, and then try to think of a way to add redundancy and/or reduce the disaster potential.
Some components will require regular maintenance (like those holes people drill in their returns to reduce flooding potential from siphoning), and you simply do the maintenance at least twice as often as you think is necessary.
Other components can be protected with back-ups (control valves in auto-topoff setups).
First, though, it is best to understand the failure potential and mechanism. Then you can devise bullet-proofing techniques.
And if you can't come up with a protection method you are comfortable with, see if there is a way to eliminate that component. (Personally, that is how I feel about siphon-overflows. So I won't use them. Personal decision.)
Some components will require regular maintenance (like those holes people drill in their returns to reduce flooding potential from siphoning), and you simply do the maintenance at least twice as often as you think is necessary.
Other components can be protected with back-ups (control valves in auto-topoff setups).
First, though, it is best to understand the failure potential and mechanism. Then you can devise bullet-proofing techniques.
And if you can't come up with a protection method you are comfortable with, see if there is a way to eliminate that component. (Personally, that is how I feel about siphon-overflows. So I won't use them. Personal decision.)