How often do I change substrate?

[Naf Eeknay]

We clean, disenfect and replace the aspen bedding after our snakes shed, so once a month, give or take...

That's good. At least it gives me a time frame. I think I will wait until he sheds then change it out. I may go with astro turf next though I like the look of the reptibark that I am using now.

Peace