I just got my first rack and have questions

As the title says i just got my first rack(used). well 3 actualy but im only using one right now. Its a 5 slot 32 qt sterilite . I dont know who makes it but its 1/2 inch plastic. it came with back heat so i took it apart and made it belly heat using 4 inch heat tape I've had it on for about 2 hours now but its empty till i get it set up right. Im gonna keep an eye on it for a few days. Maybee i'll move them in over the weekend. Holding temps at 88/78 with no substrate in it yet.

Is a 32 qt tub big enuff for a 3000 gram ball? it looks kinda small, i put a spare hide in it and it takes up almost half of the tub.

Any tips or anything i should know for a first time rack user?

I think that people would jump up to the CB-70's for that. I would also bump the temps up to at least 90F. Do you have a temp gun? Very important for racks, in my opinion.

its only at 88 cause im testing it empty. for some unknown reason that was where i took my finger off the button