Pricewise its a good value filter with a high turnover. I have one FX5 and 2 pro 3s. The Eheims just run and run whereas the Flu died a couple of times. had to wash the impeller out and it was OK after that. What actually happened is that the ceramic rings disintegrated after a while and bits of sand got lodged in the impeller well causing it to grind to a halt. In short the Flu needs more frequent servicing than the Eheims, ones a Fiat, the others a Mercedes