The last time I pulled my centerpiece out of my ten gallon to scrape it off (driftwood with anubias on it) I noticed a slight odor... It smelled a whole lot like patchouli. I came home today and I can smell it anywhere in my bedroom, and it smells like it's the tank!
No hippie jokes please!
I have been dosing the tank with Melafix, could that be the cause?