How to make a little light for a small jar

[Benji k]

So I was just setting up this little jar that I was going to aqua scape but what light do you guys use and can I use potting soil for the substrate.

 

[Fishmanic]

how big is the jar? pic?

 

[Benji k]

how big is the jar? pic?

Oh it’s only about a 2 litre circular jar I don’t have it rite now I’ve been thinking of setting up a little jar but I might just set up and aqua scape a really big fish bow. I love the look of established full grown out plants in an aqua scape .