Elos 120 sump configuration

[YHSublime]

I bought this tank as “new to me” and I’ma little confused by the configuration, or at least what is suggested. Also, if anybody knows the make?

 

[YHSublime]

The 3 boxes on the left hand side are open on the bottom. The “third box” about the middle has a hole into the main smaller chamber. The partitioned right hand side is all one section, sans a hole up top in the baffle into the section on the left (like an ATO holding section almost.)

in terms of configuration, the overflow can either drop into the larger open space on the left, or the larger open space on the right.

 

[YHSublime]

Guess nobody else knows either? I'll admit, it's a doozy.