Overflow sucking

ShipWreck2 · 02/21/2013, 07:56 AM

So I have built a 400g tank with an external overflow box. The box has 2 1.5" bulkheads in the bottom and a third one on the side as an emergency hole. I am using a dart pump for the return. Just after the bulk heads outside of the overflow box I have a T with one side continuing to the sump and the other rising above the water line for an air intake. One of the two bulkheads is raised slightly higher so almost all water is going through the one drain. This works well but ocassionally a little vortex forms and it pulls in air making a loud sucking noise before goi g back to normal.

Any suggestions on how to fix this?

azjohnny · 02/21/2013, 09:13 AM

you are overwhelming the drains, back off on the flow from the return pump

super_steve85 · 02/21/2013, 03:49 PM

What size is your air intake (vent?)? It sounds like you are running an air-assisted drain and not a full suction. Right? If you are going the air-assisted route, it sounds like you aren't getting enough air through your vent to prevent a siphon from trying to form. If you are using a cap with a hole on top of your vent, trying making a bigger hole...or taking off the cap to see if that solves your problem.

02/21/2013, 07:56 AM	#1
ShipWreck2 Registered Member Join Date: Mar 2005 Location: Ontario's West Coast Posts: 92	Overflow sucking So I have built a 400g tank with an external overflow box. The box has 2 1.5" bulkheads in the bottom and a third one on the side as an emergency hole. I am using a dart pump for the return. Just after the bulk heads outside of the overflow box I have a T with one side continuing to the sump and the other rising above the water line for an air intake. One of the two bulkheads is raised slightly higher so almost all water is going through the one drain. This works well but ocassionally a little vortex forms and it pulls in air making a loud sucking noise before goi g back to normal. Any suggestions on how to fix this?

02/21/2013, 09:13 AM	#2
azjohnny Registered Member Join Date: Apr 2012 Location: Gold Canyon Posts: 2,914	you are overwhelming the drains, back off on the flow from the return pump

02/21/2013, 03:49 PM	#3
super_steve85 Registered Member Join Date: Jan 2012 Location: Monroe, NC Posts: 132	What size is your air intake (vent?)? It sounds like you are running an air-assisted drain and not a full suction. Right? If you are going the air-assisted route, it sounds like you aren't getting enough air through your vent to prevent a siphon from trying to form. If you are using a cap with a hole on top of your vent, trying making a bigger hole...or taking off the cap to see if that solves your problem.