I used it in my emperor, just before the cartridge and it removed all the tannins leached from driftwood. Within 24 hours when from light tea to crystal clear.
OH YEAHH I HAD IN MY SALT WATER TANK I PLACED IT IN MY WET DRY RIGHT WHEN THE WATER FALLS DIRECTLY ON IT AND IT WORKED GREAT CRYSTAL CLEAR WATER AND HEALTHYTANK AWSOME STUFF I HIGHLY RECOMMEND IT