What would cause the plastic inside the grids that are 1 week old to break on a Hayward pro-grid series DE filter?

Possibly the system is "over pumped" meaning, too much horsepower or waterflow in GPM for your system. Need to know size of pump in hp, size of filter in sq. ft, size of plumbing in inches (ie 1 1/4", 1 1/2" , 2", 3"), Does the system have a heater? Sounds like the system is not balanced for hydrolics.