Second hand sump help

[ultrasuede]

Hi,

I bought a second hand tank and sump. I can't get my head around how this sump works. It has 4 separate compartments in the usual spots but it also has a compartment running along the back. The seller called this compartment a 'mud sump'. Never heard of it.
It also has the gaps that allow the water to flow between the compartments, but they all run along the bottom.

The back 'mud sump' is isolated from the other compartments apart from 2 threaded holes on either end of the sump.

Any advice would be appreciated.

 

[Ron Reefman]

I've seen one similar to that before. The back area was used to run water from the drain (inflow) directly to the return pump, bypassing the refugium. The idea being the drain has a filter sock and the return had a skimmer, so all the water got some cleaning done. But they wanted slower flow through the refugium, thus the bypass.

 

[ultrasuede]

Thanks Ron. That makes sense. Any idea why the gaps between the sections are all at the bottom? My understanding of a sump is that each section flows from bottom to top. This design seems to flow from bottom to bottom.

 

[Ron Reefman]

Nope. It doesn't make any sense to me. The idea behind the walls is to separate the sections. This system ties them all together and the water level would rise and fall the same in all 4 sections. And if you use one as a fuge, algae can get under the wall and into the return section.

I'd add at least 2 new walls that would go from the bottom up to whatever level you want to hold behind the wall. That way water would flow over the new wall and then by forcing it down under the existing wall it will reduce the amount of bubbles that get transferred along.