AVOID ADDING TOO MUCH DE POWDER - One of the most common causes for getting DE Powder in your pool is adding too much DE powder. Check your owner's manual for the manufacturer's recommended amount of DE Powder. If this is a new installation, you will have to add the full recommended amount. But if you are replacing DE Powder after a backwash, you will not need to add the full amount - generally around 80%. The grids will have retained some of the DE Power after the backwash, and if you add too much, it may end up in the pool. Use the DE scoop that is generally provided with the DE Powder to measure the amount of DE Powder to add. A 1 lb coffee can is not equal to a 1 lb DE scoop. Another guide to assess how much DE Power to add is to monitor the pressure gauge. Stop adding DE Powder when the gauge hits your normal operational range - generally 10-13 psi.