Hi , soaks times are different for different type of seeds. I would not mix my seed if I were you. Oats is much lighter than wheat. I believe it requires a shorter soak and if mixed in with wheat I think the wheat will dominate the water resources. I have found 3 things that primarily effect the sprouting. Soak, growing temp and tray design and volume. If you manage those three things it is full proof assuming of course your starting out with fertile seed. Feel free to call me @ 701-317-0240 and I can maybe we figure out quicker what's happening. Thanks, Mike