Two tanks sharing a single sump -> Overflow safety?

[Seewolf]

I am planning the plumbing of my two new 100G tanks.

Each tank has a single overflow and I plan to pipe both overflows into a single, shared sump (the sump is also shared by a third tank, a 20G refugium).

Now my worst case scenario game: When one of the overflows, for example the one in Tank 1 cloggs, the sump is still fed with water from Tank 2. The result will be that Tank 1 will overflow... Is there a trick to prevent that this happens? The same is true with the refugium: clogging of the refugium's overflow will be even worse -> The refuge will still be fed from the sump, which is being fed from both main tanks...

Is a shared sump a ticking bomb?

- SW

[yaktop]

shared pump no, single overflows maybe, no less than single tank would be. you will overflow the same just lots more water. put in two low water shutoffs, either one gets to low shuts the pump off. then you have anothe problem unless you have a closed loop on each. many diy threads on shutoffs from using radio shack or grainger parts.

[Seewolf]

Another thought: I could build a safety overflow for the sump. When the level reaches the safety zone, the water drains into another container large enough to prevent a flood...

[yaktop]

best solution. stop the pump - as long as you have a closed loop. i