Below is the freshwater tap located on the Northeast corner

Below, the southwest corner with a water return outlet

Blue arrow: heater
Red arrow: filter
Yellow arrow: pump

This pool equipment is located in an enclosure beyond the southeast corner of the pool. At the moment, I am not sure what if any of the equipment can be adapted/salvaged for the biofilter.

Below, the southeast corner and the surface skimmer intake

Below, the west side. Arrow points to water return from pool filter

Below, a view of the southwest deck area. Arrow points to AC electrical outlet. Perhaps the biofilter can be located here, and I would build a cedar or redwood enclosure to hide it.

And, yes! I am going to remove this old diving board