siphon break with built in overflow

[daninct]

I am setting up my first drilled tank with a built in corner overflow (90 gal marineland). Is there any chance of a siphon break to stop the overflow? I am concerned about having my return pump overflow the tank as the sump return does hold more water than the tank can hold.
In my prior setup (75 aga) with a HOB overflow box I did lose siphon once in a while but I had thge sump return set at a few gallons and once that water went to the tank and it r an dry I was all set. I used a small maxi 1200 with 3/4 tube.
I didn't do that this time (I removed the baffle) as the larger pump (MAG 7) drains that small well way too fast. I am using PVC 1" pipe.
Any thoughts?

 

[rbaldino]

I don't quite understand the question. Are you concerned about the overflow stopping, or about the return line sucking water down into the sump in the event of an outage?

 

[darknes]

A drilled overflow doesn't use a siphon like a hang-on back overflow. The only way you wouldn't have water drain from your display to the sump would be if the drilled holes got plugged.

 

[daninct]

I was concerned about the overflow stopping. That would cause my return pump to drain the sump all into the DT and I do not have that extra capacity in the DT for the entire sump volume. I think Darkness answered my question so I am less concerned now about having too large a return section in my sump/fuge.
Thanks all.