Shelley, On B&W darkroom contamination isn't such a source of trouble. Keeping different trays and graduates for developers and another set for the rest will obviously minimize risks and save you a lot of water for cleaning purposes. If you play a lot with toners, it may be wise to keep a tray just for that. Developers are more sensitive to contact with other chemicals, due to the risk of changing PH and it's working strengh. Good work.(posted 8419 days ago)Cesar B.