But, nice snail btw, BUT, when the power is off, NOTHING should overflow. Snail in the return (to sump), should/could make the DT high/overflow. But in a power out, things should just equalize, snail of no snail in the return pipe. I'm missing something here. If you have an secondary/emergency drain= it should have been flowing more doe to the snail in the main return. Looks like a herbie/durso maybe?