So i finally got around to fencing off my slime in the Hutch. Seems to work well. The only problem is that you still have to enter the pen to put eggs in the incubators. Ah well. i just try to lead them to the other side first, then I run back and toss the eggs in real fast then get out. I can confirm what was said earlier that the slime don't have to physically have access to the water to make slimeballs.