Have a TCP taint from a pet fermenter, the second its happened to. Reckon it must be VWP related as chances of two infections taking hold seems improbable. I've cleaned and cleaned, washing up liquid, oxi, campdened. But cannot get chlorine out of the walls, leave water in there for a few hours. And I've got a swimming pool. Anticipating another tank to be chucked as a result. So that's a concern, polarity of PET and chlorine means it's stuck and i can't break it free. With stainless its not permeable so preferable. Thinking I'll pick up a 23l keg and ferment 19-20l batches in there.