when I pull some water out it looks clear. I think it was the yellow color from a mix of driftwood and dead plants. I am thinking this because the tank is a lot clearer then it was yesterday. Plus I think my oto-cats have been at work with any algae in the tank. I was in the tank all weekend trimming and cleaning. I am sure I didn't get all of the cuttings out. I will run out and get all some activated carbon.