Look for polybiomarine polyfilter much better than carbon will quickly adsorb/absorb tannins, organics, Phosphates etc we use them here in the states they turn color according to what they adsorb/absorb have used them for 20 yrs They are great and many high end aquarium stores, and Medical researchers including myself use them, I stack them in series in Eheim or aquaclear filters . Good Luck!!!
Bookmarks