Filter change, DE to Sand.

I took my pool cover off for the season to find my spa and pool coated with DE. I've been sitting on the fence about a change to a sand filter and now I'm going to do it. I've spent my last dollar on the DE filter. My question is will the DE in my pool contaminate the sand media in my new sand filter and cause the sand to have to be replaced; or will it backwash out when I service (clean) the sand filter. There is quite a bit of DE in my pool and I haven't installed the new sand filter yet.