Random margins between images

I don’t want these margins to appear between the grid row and full screen slider placements.

portfolio page: ccyran.com/portfolio

you’ll see that there’s a black space between the full width slider and the 3 images. There’s also a black space between the 3 images and the “Galaxy View” fullwidth slider images. You can’t see it there though because the background of the Galaxy view work is black.

Please help me fix this! It’s going to give me some headaches down the road. Thanks!

Screenshots:

http://postimg.org/image/qy49o73rr/
This one highlights my images so you can see where the gap is

http://postimg.org/image/6jgz4lzh3/
This gap is the same size