Hello
Twice a year I'll run my Diatom filter for a few hours, I'll take a power head (Hagen 801) with a 12" hose attached and blow it into all the nooks and crannies. I always get a huge detritus storm, change 25% of the water and were good for 6 more months or so! My 75 gallon tank is going on ten years, and my 125 just turned 7 years old.