Grit in the fuel tank

Have had issues with the fuel pump going out on the front tank for a few years. Pumps were not even lasting a year. Think and hope the problem has been solved. When replacing the fuel pump there has been a fine type grit in the tank and tank has been flushed but the grit would be back again next time. No corrosion at all on the inside of the tank. This time it was discovered that the flexible fill hose and vent tube had numerous small cracks. We believe and hope that this is how the grit was getting into the tank. So as a tip when you pull the tank check those two line very carefully.