I just want to keep this community active by posting a picture of Blasbert.
I got a jar of sand from the sea. It's probably around ten years old but let's see of there is still life. I will take some and put it in saltwater. For example copepods sometimes lay eggs that can survive up to 20 years without any water so I hope that at least something will hatch...
This ecosphere is more than 6 months old and I think it's too healthy because the aquatic isopods and bladder snails don't find anything to eat so their population went down. Water is clear and got no smell at all.
Plants are growing fast and snails are eating algae all the time so it looks healthy so far.
Lake Constance is full of killer shrimp (invasive species) but since they're aggressive to pretty much anything and eat plants if nothing else is available I made it the new home of Hyalella azteca which are probably 1/3 the size of killer shrimps and fit so much better in jars.
You can configure Syncthing to keep deleted/changed files for some time. So you could connect a Raspberry Pi to store everything read-only.