what are dead areas in aio chambers for?

[mizimmer90]

My AIO unit has a region with little flow going to it, labeled 4 in the sketch:

What is this chamber typically for? I am using a sponge in chamber 1, carbon media / ceramic balls in chamber 2, and a thermometer with the return pump in chamber 3. Is there something I should put in chamber 4?

 

[Tamberav]

My AIO unit has a region with little flow going to it, labeled 4 in the sketch:

What is this chamber typically for? I am using a sponge in chamber 1, carbon media / ceramic balls in chamber 2, and a thermometer with the return pump in chamber 3. Is there something I should put in chamber 4?

more just there to help keep the pump from running dry/more leeway for evaporation.

 

[EagleEye121]

Always wondered the same. Maybe just to add water volume to the total system and help prevent the return pump from running dry. You could add some bio media there for extra surface area

 

[Tcook]

Yes. More volume to deal with evaporation. In my IM Nuvo 14 the body of the pump slips under there so I can fit a Tunze ato in the vertical section.