One of the Saubermann secrets of the Exo Terra Turtle Filter FX-200 terrarium filter is the double activated carbon insert, which leaves no chance for harmful substances. The activated carbon filters all heavy metals from the water and does not increase the phosphate content of the water. The result: crystal clear, clean water in the aquatic terrarium, paludarium and turtle tank. This enables aquatic reptiles to develop healthily. This strong activated carbon double heart removes organic impurities with the highest effectiveness. You will also notice the difference in the optical quality of the water in the terrarium: crystal clear and without any turbidity. With these activated carbon inserts, the Exo Terra Turtle Filter FX-200 Terrarium Filter can always deliver its highest performance. Change the inserts every 2 months so that the water quality always remains at the best level. The Exo Terra Turtle Filter Dual Carbon Pads are cheap and strong - you shouldn't even experiment with them.