RBWL

I am not new to photography, but have taken a long break from the darkroom. I used to discard my developer after processing a roll of black and white film. So I never experimented with just how many rolls I can actually develop in one batch of chemistry. For this question let me say that if I process a single roll of 36 exposure film in a single reel Nikor tank, which holds about 8oz of chemistry. If I use the developer again how many rolls can I process before I have exhausted the developer?