Quote from nicknicknickh
So in 1.9 Pre 3 the stupid bed rock emits a glowing blackness.. and the slimes finder does not work with it(endless someone says otherwise).
Guys is it possible to find them without obviousy spelunking through every cave
The same way you were supposed to find them before.
I'd suggest going down and clearing out a large area at 13-16Y, you'll get a pile of diamonds, gold, and more likely than not find a slime spawning chunk.