disinfecting for amphibians?

[LISA127]

I have an old small tank here that has been sitting in the basement. I've kept reptiles nearly 20 years but am not much of an amphibian person. If I wanted to get some type of amphibian, how do I go about disinfecting this used tank? I understand you have to be careful with amphibians. For reptiles I use chlorhexidine but that cannot be used in this case. So what?