How often should you backwash a sand filter when fighting algae? It seems well agreed that once the water is mostly clear the dirty filter effect helps you get the smaller particles that are left. What about when the water is a total green swamp?
I have seen advice about this go both ways, backwash frequently to keep the flow higher, and let your filter get dirty so it filters better. My theory is that a clean filter allows more flow, which means more large stuff filtered out. Other people appear to say no algae is small and you need the dirty filter effect to filter it out.
There are really two different definitions of "filters better" going on here. Normal day to day operation you want to filter the smallest particles you can, so that is better. But with a green swamp you want to get the largest volume of junk out and are willing to leave the small particles for later, so speed is better.