Adding a Sump and Overflow Weir

PingG25 · 08/08/2018, 10:34 AM

I want to put a sump tank into my system. I have no installed weir as well as no holes drilled. It’s not practical to drill without disrupting the whole tank. I’m considering the Tunze Overflow Weir but unsure on the water return pump. My question is, if you get a blockage on the weir what stops the return pump from continuously pumping to the point it over fills the main tank. Hopefully what I’m asking is clear and any help would be greatly appreciated.

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Vinny Kreyling · 08/08/2018, 11:17 AM

As far as the weir - unless you feed something like larger shrimp there should be no problems with clogging, the slots are usually 1/4" wide.
You can also use a weir with no teeth under the water level by around 1/4".

2000se · 08/09/2018, 05:42 AM

Nothing in that case.. However, you could use a float switch to turn the pump off it it reaches a certain level. Even something like the VarioS 2 or 4 pump that comes with a float switch..

mcgyvr · 08/09/2018, 10:21 AM

When done properly you design the size of the return pump section so that the pump runs dry before the main tank overflows.. plain and simple..
If no water is coming down the overflow.. No water can keep filling up the return section so it just pumps out the water thats in there and then starts sucking air and voila..

Simply calculate how much extra water from normal water level it takes to overflow the tank and ensure your return pump section is smaller than that..
To be specific you look at the point in which the return pump starts to suck air (that could be with 3-4" or more of water still in the return section)..

Overflows/weirs DO fail and do clog,etc... plan accordingly..

08/08/2018, 10:34 AM	#1
PingG25 Registered Member Join Date: Dec 2014 Location: Rugby Posts: 92	Adding a Sump and Overflow Weir I want to put a sump tank into my system. I have no installed weir as well as no holes drilled. It’s not practical to drill without disrupting the whole tank. I’m considering the Tunze Overflow Weir but unsure on the water return pump. My question is, if you get a blockage on the weir what stops the return pump from continuously pumping to the point it over fills the main tank. Hopefully what I’m asking is clear and any help would be greatly appreciated. Sent from my iPhone using Tapatalk

08/08/2018, 11:17 AM	#2
Vinny Kreyling Registered Member Join Date: Nov 2002 Location: Miller Place, NY Posts: 7,206	As far as the weir - unless you feed something like larger shrimp there should be no problems with clogging, the slots are usually 1/4" wide. You can also use a weir with no teeth under the water level by around 1/4". __________________ 250 gallon mixed reef, 2 Reefbreeder's Photon V 2, Deepwater BLDC 12, DAS EX-3 Skimmer, MTC mini cal, 2-3/4" Sea Swirls, Aquacontroller & 6 Tunze pumps.

08/09/2018, 10:21 AM	#4
mcgyvr Registered Member Join Date: Sep 2003 Location: North Carolina Posts: 20,050	When done properly you design the size of the return pump section so that the pump runs dry before the main tank overflows.. plain and simple.. If no water is coming down the overflow.. No water can keep filling up the return section so it just pumps out the water thats in there and then starts sucking air and voila.. Simply calculate how much extra water from normal water level it takes to overflow the tank and ensure your return pump section is smaller than that.. To be specific you look at the point in which the return pump starts to suck air (that could be with 3-4" or more of water still in the return section).. Overflows/weirs DO fail and do clog,etc... plan accordingly.. __________________ Who me?

08/09/2018, 05:42 AM	#3
2000se Registered Member Join Date: Feb 2003 Location: charlotte Posts: 532	Nothing in that case.. However, you could use a float switch to turn the pump off it it reaches a certain level. Even something like the VarioS 2 or 4 pump that comes with a float switch..