System -> Global -> Source Type -> Sub (Bass), if you haven’t already. It will help to ‘tune’ the filters.
For the ‘natural’ sounds of an acoustic bass, I might try the Hall or Room algorithms first. Built-in EQ adjustments. Choosing Room sacrifices some control over the mids to gain control over the early / late reflections. You may prefer to dial out the low end reverb decay, as it can easily turn into competing mush.
I am kind of partial to a reverb bloom, using a small Blackhole, Inv-Gravity at 0. I would think that most reverb for bass will benefit from being on the smaller side, barring special FX. The important part for me is that each of these algorithms (including the SP2016 suggested above) has Pre Delay, to put separation between dry & wet.
Some suggested starting points. Experimentation is key. You may end up preferring the high metallic sheen of a Plate, that doesn’t step on the bass. Or some rattling of Springs (with or without tremolo) for more of a classic ‘amped’ sound. A heavily effected bass? ModEchoVerb.
