FNS filter size


Active member
Aug 26, 2016
San Diego/CA
Can anyone help me out with a hopefully simple question? Bought a house with some aging pool equipment. There are no markings on the filter but figured out it was the FNS Plus. It measures 48 inches to the top of the tank (56 to top of the gauge).

I found a manual online but could only find info about installation clearance and size of filter grids. No info about external dimensions of different models.

Can anyone tell me the model and sq ft. For this filter? I need to know how much DE to add.