I have just received sepia, blue, and copper toning chemicals by fotospeed. What is the minimum amount of fluid to tone 7x5 prints in 10x8 trays? I don't want to waste chemicals, this is especially for the blue and copper toners which must be discarded after use. For the other chemicals (bleach etc), should I mix up the whole lot and store them or what? Is it best to tone straight after washing or the next day? (following a soak) If it makes any difference, I'm using Ilford mgiv paper fb gloss, and rc pearl. Many thanks to anyone who reads or replies.