power loss water for sump/fuge....

I just finished the baffles for my sump and filled it with water to just below the return section baffle tops. Then filled it up to see how much water space I had left in case of a power outage. I ended up with 4 gallons of water space till I reached the top.
I have a 72g with a 900 gph overflow box and I'm planning on 2 return lines. Is putting the siphon break about an inch from the water line in DT good enough?

 

What is the depth of your tank? Divide the 72 gallons by the height to get an estimate of how many gallons will flow back into the sump.

I am guessing that the tank is at least 18 inches deep, sooo you will most likely be OK with the siphon break 1 inch below water level.

 

Thanks..... I hope so. lol

 

I'd put the siphon break at the same level or slightly higher than the lowest level of your overflow box.