6th March 2005 at 12:23 pm #633
That’s what we though as well, but interviews showed it was not really necessary for the user. Once the filter runs, they hardly ever have to maintain. Many of them also would not have the money for two filters. And everything is also a matter of comparison. Even if the user doesn’t wait for four weeks, the water quality is still much better than the raw water. Often it is also just enough to stir the sand a bit, which causes a faster flow rate again, but the water quality improves quickly. I know this is quite against the literature, but we found out the schmutzdecke is not as disturbed as you might think.