Remember the jar experiment?

I’ve been a bit delinquent about jar experiment updates. I started with a sealed jar full of water from my fish tank here. It has been sitting on my desk ever since. A long time passed until anything grew. Now there appears to be two types of algae, a forest green scum on the sides (which can be seen in the picture) and something thick and black along the bottom. I must admit, I don’t feel inspired to open the jar as I fear what it might smell like.