I've been battling with a phosphate issue for the past year on my RSM 250 and started using Phosphate RX in the tank. I was a little wary to start with as its a chemical solution but after about 10 days I've gone from 0,9 PPMs to 0,02 with no ill effects on any inhabitants in the tank. I have barely needed to clean the glass for a week! I'm now considering using the Clear FX Pro and replacing the carbon bag with this product. Does anyone have any experience off this product over a longer period.