Well, I've just made it back to the pond. I think I can rule out bag dust. The food is disappearing at about double the rate it should and much of the feed is coming out crumbled or dusty still. I think I'll let it run empty and investigate further. Maybe about 6 weeks back, I arrived to find one of the buckles on the lid was unbuckled and that side of the lid was ajar. I figure some bugs made their way in then.
