My closest pond doesn't have many good plants, so this was pretty tough. I tried a piece of grass which I think I did get from inside the pond but I don't actually think grass can survive under water for long?

Month 1:

I think the cone shaped snails are trumpet snails, I grabbed more than I would have liked since they hide in the dirt. I did move some of them to a different jar.

The little shrimps (scuds?) laid a bunch of eggs, they seem to reproduce like crazy.

I got some bladder snails(?) and a chunk of algae from a friend's local pond. I don't think I've ever opened the jar after that.

Month 3:

The trumpet snail population was declining, they seem hard to keep alive.

Month 4:

The water got murky green, probably floating algae. Later I tried to reduce sunlight slightly by moving the jar to make it easier to see.

The snail population is low but it's not a big jar. Maybe it's stabilized. But that's all for now!