I have an inground 6k fiberglass pool, with a Jandy 1 1/4 HP pump and Tropicflo cartridge filter. I'm needing to clean my filter weekly to keep the pressure from building. I was dumping some water and left the cartridge out and flow was amazing. I've had the same problem every year, with different brand cartridge replacements, We only have a 4 month pool season here in Michigan and I change them annually. Any ideas? Thanks