6th March 2005 at 12:02 pm #612
Through my water analyses I found out after four weeks all filters have established a schmutzdecke to such an extend that drinking water quality can be obtained. Some filters are ready earlier. It depends on certain factors. Users are instructed to continue boiling the filtered water during the first four weeks of filter usage, because after 4 days the water is at least physically clean and it would be a waste to discard this water.
Generally the users know it is time to clean the filter, when the flow rate to so little, that is does not meet the water needs of the family anymore. Only then it is really necessary, because the more time the water has to pass the water to cleaner it will become. In raining seasons the filter sometimes blocks completely, because the raw water was too turbid.
The user is thought how to clean the filter himself, because before they buy the filter they undergo a seminar about maintenance. They will remove the top 5 cm of the filter matrix and was it in water several times. After this they apply the sand carefully again and start with the four weeks cycle. In some cases filter start to develop a crack and therefore leakage. The user will have to remove all the sand and seek a technician for help.
Cleo