You can buy a prism at a science supply store, a hobby store, or online. Basic prisms are relatively inexpensive.
Alternatively, you can put the water in a tub or other container. If you do this, place a mirror in the container and submerge it halfway at a 45 degree angle. [8] X Research source
If you are using a mirror in a tub, place the paper above the mirror to see the light when it refracts.
