What would cause a GFO reactor to suddenly have a low outer water line? Media was still tumbling in the core when I checked it this morning but the water line outside the tube in the canister is low. Typically there isn't much air in there but from the photo you can see it's about halfway down. If I close the ball valve on the output line it will rise some, but not all the way to the top. Opening the valve causes it to drop again. Haven't seen this happen before.
