I have never kept a snake in a tub, but please make sure there is enough ventilation!! It will help with the humidity for sure like djc reptiles said.
My boa puked years ago and it was the most peculiar thing. Not sure why to this day. I cannot see the picture, but her puke looked, legit, like a frozen mouse had just been laid down on the floor of her tank. It was completely thawed and warmed up when icfed her a few days before, i know I didnt feed her a part frozen mouse. She had mites at the time, so just paper towels on the floor so i could see them. I went to pick it up, inverted Ziploc bag over my hand like a poop bag, grabbed it, and it was like that liquid marshmallow spreadable goo. The weirdness in me was fascinated, yet completely grossed out since that wasnt what I was expecting to touch!! She obviously didnt have much time to digest it before this happened. And it was directly on the glass as she had so nicely moved the paper towels out of the way as not to dirty the wonderfullu trashable part...
As weird/gross as it is... Can you try and describe it if you can't get a picture to load? It would really be helpful. Pandora has never had a poop that looked partially digested, rather she has a brown poop and a white poop (what i understand as urates. I just call em white poops...)
Also.
1) what snake?
2) is your heating correct for said snake?
3) it is totally normal to freak out about these guys. I only had 1 friend with reptiles that got me into this, i poured TONS of questions on him because i had no one else. and he didnt know it all, just what he heard and read! Do some research! Get some books!! Even second hand book stores have a ton of stuff.
Do not hesitate to ask, lots of people on here are way smarter than i am. I've had Pandora 10 years now and i still find myself asking questions. They are the most precious little noodles that fit so cutely in the palm of your hand and before you know it they turn into mommy's little monster, devourer of hope for rodents!!
Good luck with your sweetness, i hope to see you reply soon with some kind of good news! And/or more questions!
Kali