There’s no need to worry about the water being gross in a used hot tub (after being properly sanitized), but there is good reason to be concerned about there being a disgusting rat infestation beneath the shell. You might be surprised at how biohazardous this can be. Seeing and smelling what’s under a rat-infested hot tub and behind the panels may result in the need for PTSD counseling.

Pestworld.org explains that being around feces from mice and rats can spread bacteria, trigger allergic reactions, and cause serious health problems. Even once the urine and fecal matter become dry and undetectable to the senses, it can still be hazardous to those who breathe in the airborne particles. So, it’s not just the emotional aversion or persistent smell you need to consider, it’s the toxicity that can spread diseases and viruses.

Sometimes there’s no way to tell if a hot tub is infested with rats unless you look underneath it and take all the panels off.
No need to worry if you buy a used tub from Hot Tubs Galore, but if you’re considering buying privately, keep that in mind. Check out 3-P: Sealed Bases for more on this topic