where did u get the purigen i quit using carbon of any kind about 3 months ago and i have not noticed any difference in water clarity i mean i have crystal clear water. i do 30% water change on sundays and a thorough gravel vac on wed or thursday and have not had any problems at all but i am always up for new ideas.
You can get it at petsmart or local fish store . it made by seachem and I too thought my water was clear, this stuff brings water clarity to the next level. best part it can be regenerated with bleach!