When the original filter is oriented on the build plate so that the internal 20mm (1/2") thread is upmost, there is an overhang which required support which would end up internal to the filter.

I have simply created an angle within the model so that the overhang can be printed without support.

Fits the submersible pump's external 20mm (1/2") thread like a glove!

Thanks to Gromina for the hard work