Based on what I understand, Kelly is right on the money. The key is water quality and being sure it can be resuspended/resulubilized if it fell out of solution. However, I would be inclined to spray it out (so it is not dumped in one spot) and use a fresh tank, unless you have time for a respray after you see what it does.

http://www.cdpr.ca.gov/docs/emon/pubs/fatememo/glyphos.pdf