I replenish per sandy king's article on kallitypes. I keep a second bottle with the appropriate amount of dichromate in it for topping off.
I want to try the cot-320. Does it need an oxalic acid bath for kallitype? Unfortunately I had no luck with the stonehenge rising, maybe I got a funky batch? I also had no luck with the artistico. Crane's platinotype is OK with no oxalic acid but I find the paper too delicate and I have to handle it very gently.