Changing from gravel to sand!

[dipsydoodle]

I’m thinking of changing my newt tank substrate to sand from gravel (too big for them to eat). I’m just wondering to newts actually have a preference and would it harm them if they ingested any of the sand accidentally?

They are chinese fire bellied newts. I fancy doing a bit of a tank re-scape and sand would lighten their tank up brilliantly.