How far apart do the cakes need to be set? I have a small tub that would fit 6 very good but the thing Is I have 10. I may buy another tub and go 5 and 5. But some people's chambers have the cakes almost touching and some have them widely spaced. Is there any true effect from spacing? Won't the mushrooms find free space naturally.

Give them 3 or 4 inches between. You can go closer, but ideally you want to give the little guys enough room to grow.

If your cakes are short and squat, you can stack them too.

Alright thanks