Will plaster of paris harden enough to hold water?

Question:i am makeing a fountian, and need to know what to use to mould it

Answers:
plaster of paris won't do well.

After several day it will hold water for a while... but water will resoften the plaster and it will crumble with prolonged exposure.

Use "Portland Cement" mixed with fine white sand or even glass beads meant for sandblasting if you want a very smooth nearly white fountain.