Frag tank below sump

[WillH]

Anyone have any experience or examples of how to do a frag tank that sits below the sump level? I am not sure if its possible but curious.

 

[nautical_nathaniel]

Anyone have any experience or examples of how to do a frag tank that sits below the sump level? I am not sure if its possible but curious.

You could build an overflow in the sump that flows to the frag tank and then install a return pump in the frag tank that goes to the display tank or back into the sump. You may want to install the overflow after the mechanical filtration section of your sump.

 

[ca1ore]

I would not recommend it. Lowest volume ends up acting as the collection for all overflowed water. I'd have to think about whether an overflow feeding the frag tank from the sump would work or not. What happens if the power goes out? All the drain down would end up in the frag tank, so you'd have to size it properly. ATO would need to be there also.