Do bio-filter balls for nitrate removal have to be replaced after a while?
No, it is not necessary to replace the JBL BioNitratEx filter balls for nitrate removal. The balls are broken down by the bacteria and the carbon source they contain is used for nitrate removal. After 6 months you’ll need to refill the missing quantity (1 ball per 2-3 l water). Please do not remove the remaining balls, as they serve to inoculate the newly added balls. Please note that the balls need to be embedded in a layer of fine filter fleece so that the smallest parts of the degradation do not get into the other filter material. In marine water, the additional use of activated carbon is recommended to avoid initial cloudiness.