I'm using my usual 1:9 dilution for selenium toner. However, based on an earlier experience w/Forte Polywarmtone, I kept a close eye on it. I found that 3-1/2 to 4 minutes was fine, but as I approached 5 minutes, the color change started to take off. Like the Polywarmtone, it goes red. Just the slightest hint of the red, however, is kind of nice.