The worst filter experience I have ever had was on the Rio Grande when it was receiving a lot of runoff. The water was the consistency of a milk shake. We tried to let it settle overnight in buckets to avoid seriously clogging the filters. Settling didn't solve the problem. The First Need filters clogged within one gallon even though the water was fairly clean and we had settled it further with flock. Backwashing didn't unclog the First Need filters. A Freshwater filter worked somewhat better since we could actively brush it out before backflushing. I think they are out of business, but I am convinced that any filter that can be actively cleaned will be superior under certain conditions to one that can be cleaned only by backflushing.