Flood Prevention HOB Overflow box

jeffww · Sep 12, 2021

I'm looking to set up a overflow for a small sump to hide some equipment. If I am understanding correctly, if I put the return pump behind a baffle or into a small bucket, so long as the volume of bucket + overhead is less than the void volume, I shouldn't encounter an overflow if the siphon breaks in the HOB overflow? For my tank I think the void or headspace should be roughly 3 gallons which should be an acceptable level for the 10g sump I'm planning.

blaxsun · Sep 12, 2021

You basically want enough spare capacity in your sump such that when you turn off your return pump, the water that can potentially drain from the overflow and back through the return outlets won’t overflow the sump. A baffle and/or return pump chamber would be your best bet.

You may want to try to find some dimensions of sumps sold online that are close to what you have or are planning as a reference.

Gtinnel · Sep 13, 2021

Yes if your return pump chamber is small enough that it's volume isn't enough to overflow the display then I don't see why your plan wouldn't work. If the tank isn't already setup it seems like some outside testing would be in order to easily test your plan.

blaxsun said:
You basically want enough spare capacity in your sump such that when you turn off your return pump, the water that can potentially drain from the overflow and back through the return outlets won’t overflow the sump. A baffle and/or return pump chamber would be your best bet.

You may want to try to find some dimensions of sumps sold online that are close to what you have or are planning as a reference.

While that is true I believe the OP is actually talking about trying to keep from overflowing the display if the hob overflow losses siphon.