I was getting a ton of DE powder into my pool. Called me pool service company and when they sent their tech out, he checked my DE filter grids and I had giant hole in 1. He suggested I replace all of them since he was in there (and I did). Pool was crystal clear for about 3 weeks. Today the pool is lined with DE powder once again. Any suggestions? I’m at a loss, I saw the hole with my own eyes, grids were then replaced and even worked great.