I know carbon in not normally recommended for planted tank. I have a tank that is dense planted with java moss and bolbitis heudelotti and the plants are growing fine. there is some hair algae in it that I'm dieing to get rid of but my oto just don't seemed to nibble on it. Try keeping some shrimp in it but don't know why all the shrimp keep dieing (Despite using RO water!) The tank get a 50% water change every week and EI dosing at 50% as this tank was meant to be a low light setup. I think there is something in the tank that is causing the shrimp to die... either some chemical secreted by the plant, or stoke on trent water. anyway, I was thinking of adding carbon in the filter and add some shrimp in the tank. How does carbon affect the nutrient in planted tank? Any opinion anyone?