When I opened my pool it was green. I added shock and Algea Break 90 (which has always worked great for me). The water became clear and looks great. I accidently put too much DE in the system. White powder appeared on the bottom of my pool. I assumed it was DE. I've vacuumed several times, back washed the system, but I'm still getting the white power on the bottom. It is getting less with each vacuum, but I thought it would disappear after I back washed and added the proper amount of DE. Any suggestions?