I absolutely love this post! Very informative! I plan on using this for my current ball python (who is just in a 20 gallon glass tank for right now). If it weren't for the fact that nobody is really selling any iris Christmas tree tubs - mostly because nobody has any in stock- I would have just gone straight to that, thus I have to wait another... 5-6 months. ;_;
Anyways, I went looking for the tub that you have posted here and wouldn't you know it, my mom happened to have two of the exact ones you have... except they were out in the chicken barn. In great shape though!
One was holding empty chicken feed bags while the other had hay in it: I took the first one, but boy did it need a cleaning! There was even a dead mouse in it!

And spiders. I still have to sanitize both the lid and tub: would you recommend a bleach solution and if so, what percentage?
Also, there are scratch marks on the outside bottom of the tub (like the tub was dragged across pavement or rocks for a little bit). I also checked the inside of the tub for scratches: I didn't
see or
feel any, but I understand that there
might be some. Will I have to clean the entire tub more often or what are your thoughts?
How deep did you make the substrate? 3 inches, or more? Any other tips/advice?