Hmm... When are you trying to feed them (when do you offer the food)? Also, was their breeder feeding f/t before you got them?

I have 2 KSBs myself and although one was a slow feeder to start, they both pound food now. What I do with mine, is I feed them at night, around 9pm in a separate deli cup or rubbermaid box (started off with sand in the container, now both are on paper towel in their feeding containers). I put them in the containers about 30 mins before eating and place back in their tanks on the warm side of their enclosures. Then I feed using f/t mice wiggling it around to stimulate a feeding response. Now that they are both used to the routine, I don't have to place them in the containers so early, just right before I feed them.

I would also suggest not lowering the temps on the hot side of their cages at night. My hot side stays at 95 all the time. I also use a heat lamp to warm the air in the cage (it's an infrared lamp so it can run at night too).

Good luck!