Refugium Below Sump Designs

[PaulB777]

I have an existing sump in the basement for my 150g tank. For various reasons I needed to put the sump on the top of my shelf. I'd like to add a refugium BELOW the sump, however, I'm not really sure how to do that since I can't figure out how to balance the inflow (e.g. an overflow or siphon in the sump) with the outflow (e.g. a pump from the refugium back into the sump), of course while keeping the water level in the refugium constant and not overflowing or emptying it. Note that it really wouldn't be easy or desirable for me to re-route the return from the display tank....

Has anyone successfully done something like that? Any diagrams and/or pictures of the details that you'd be willing to share?

 

[Lasse]

I have not done it but I think it is 99 % safe to do an overflow in the sump to the refugium below. A return pump is placed in the refugium - it can go up only to the sump or be your main return pump to the DT
Top of water into the sump but the level indicator in the refugium

Sincerely Lasse

 

[PaulB777]

I have not done it but I think it is 99 % safe to do an overflow in the sump to the refugium below. A return pump is placed in the refugium - it can go up only to the sump or be your main return pump to the DT
Top of water into the sump but the level indicator in the refugium

Sincerely Lasse

I agree that the overflow in the sump is probably the best way to get water into the refugium but I'm not sure how to get the water back from the refugium to the sump. It seems to me that a return pump (refugium to sump) will do one of two things:
- Not pump water fast enough (thereby overflowing the refugium)
- Pump water too fast (thereby emptying the refugium and "sucking air")

I have very little confidence that I can tune (at least for any length of time) a return pump in the refugium to the overflow rate from the sump. That's really what the issue is I think....

 

[PaulB777]

The more I think about it I think that what I need is a pump in the refugium that operates like my basement sump pump. So it would have some kind of float switch that only turned it on when the water rose to a certain height and then turn off until it rises again. I can't seem to find anything like that though (at least for a saltwater tank). Any thoughts on that route?

 

[Lasse]

Rethink - if you place the main return pump in the refugium - you will not get down more than you pump up minus evoproparation. Level sensor in the refugium ant top of water into the sump. Can never be an overflow but the refugium must be able to take the dynamic level in the DT+sump. The same will be if you have the main pump in the sump and an internal refugium pump to the sump. Still top off switch in the refugium and top of water into the sump. In this case - the refugium must be able to take the dynamic levels both in the DT and the sump. Dynamic water must fit in the refugium if return pump stop

Sincerely Lasse

 

[Rjramos]

I have 3 set ups run display to refugium, refugium to sump below it, and sump with main pump back to the display. So opposite your title, refugium above sump design. No pumps in refugium. Water from display is split and gated, one pipe goes to refugium, the other goes directly to the sump below. I did it this way because the full display tank turnover would be too much going thru the refugium. At the other end of the refugium is a weired baffle with a durso to keep noise down. Refugium water drains to the sump below. If power fails, water stops at the display overflow, the refugium overflow, and the lower sump is big enough to hold display and refugiums overflow. In your case you have a lot of vertical room to add the refugium between display and main pump sump. In my case, stands are about 40” tall to accommodate both sumps and let gravity do the rest.