JBL Symec is a synthetic filter floss which does not release any harmful substances into the water. It is suitable for use with both mechanical and biological filtration systems in either freshwater or saltwater aquariums. JBL Symec can be used on its own or in combination with any other standard filter material.https://www.aquaristikshop.com/aquaristic/JBL-Symec/125137/
- Michael P. wrote about JBL Symec in 2017:
Very good filter material for extra clear water.
I will surely buy again.