Black layers on z-axis

Hello everyone, I would like to ask about importing data into Slicer. I have a sequence of tiffs of cells. I have converted them to nrrd data to use within the Slicer. When I load them in, their almost correct measurements load by themselves

(Volumes → More Information-> Slice Spacing) at values 1.242 x 1.242 x 1.242. The Slices, however, have a black layering on the z-axis (see photo 1). I change the layer spacing to be correct: 1.242 x 1.242 x 6, at which point the z axis elongates but the black layers stay (picture 2). How can I make the slices sit closer together so there are no black division line spaces between the slices with the data? I have another dataset with a larger single cell where this ‘layering’ isn’t an issue (also tiffs converted to nrrd dataset). Thank you in advance.

It seems that the comparison to NRRD file had some errors. You can load the TIFF stack directly, using ImageStacks module of SlicerMorph extension.