Walk into most conversations about grain conditioning and you'll hear people talk about "running the fans" like it's one single thing. It's not. What you're actually trying to accomplish with those fans changes depending on where your grain is right now and where you need it to be — and picking the wrong mode for the situation can cost you money in either direction.

If you've spent any time around grain storage, you've probably heard the term "equilibrium moisture content" thrown around — usually right before someone starts talking about hot spots, spoilage, or why the fans need to run at 2 a.m. It sounds technical, but the idea behind it is actually pretty simple once you break it down.

Moisture migration quietly damages more stored grain than almost anything else. Here's what causes it, how to spot it early, and how to prevent it.