I am building a slime farm and I am thinking of ways to stop slimes from spawning at certain areas.
Basically above each spawning level I have a 2-block high are where I do my lighting. It looks like this:
To be clear I am not standing on the roof of the spawning area.
There are a lot of spots where slimes can easily spawn, and I do not want them spawning there.
Best Answer
Slimes can spawn in any light level, so having your area well-lit will not stop them.
However, just as with other mobs, slimes require an opaque block to spawn on top of. You can stop them from spawning by lining the floor of your area with transparent blocks, such as glass or slabs.
Additionally, the three sizes of slimes require different amounts of room (i.e. non-opaque blocks like air, signs, torches, etc.) for them to spawn:
So, another solution is to simply fill in the area as much as possible.