I asked this same question because I bought a used tank as well. See my post on page two of BP Husbandry:
Advice Needed Regarding a 2nd Hand Reptile Tank

Started by LeeAnnT99, 11-17-2019 02:14 PM

I was given a lot of good advice and my tank turned out great. Also, I left it out overnight (where the temp dropped below 30 degrees) after cleaning just to be sure nothing survived. Hope this helps!