Originally Posted by SilverbackMel
That would be a heck of an insulation issue for it to rise 10 degrees in 30 minutes!
X2. I've never heard of one dropping that fast without some other issue involved. It's got to be spilling from somewhere. If it was the ammonia they would definitely smell it.
One other trick is to put dry ice in a shallow bowl of water and close it up in your reefer. It might help to detect any seal issues.