Eheim automatic feeder question

[someotherguy]

The Eheim auto feeder seems to get a lot of good reviews, so I picked one up for a vacation soon. I got the double barreled one to feed two different foods. The problem is that it doesn't appear to be able to feed small amounts. I feed very small amounts of pellets (barely more than a pinch). On the feeder, once the hopper is filled, it seems that the smallest increment that can be fed is one complete turn of the screw, which will dispense a lot of food. Is there any way to have the screw turn less than one turn, or any other way of having it dispense smaller amounts?
As well, the instructions that come with it make a somewhat cryptic remark about "Define the feed quantity", and shows an image of a finger pushing the + sign. I have no idea how to interpret that.

I would appreciate anyone else's help on this, otherwise it's going back to the store.