Does any know about this sump and skimmer?

[Steven Goff]

 

[Steven Goff]

I bought this equipment used. I believe the skimmer is working (after I cleaned it). It blows bubbles.

However,

I don't know much about this sump except inputs (I need a sock from LFS), the big chamber for the skimmer, and the last chamber for two pumps (tight fit). But what goes into the other 3 chambers?

 

[legionofdoon]

Quick answer, whatever you want.