I know 2 guys that have them and they both say they are great.... I just ordered mine today.
I am going to make my own for carbon.... water filter housing with DI
resin cartridge filled with carbon then I will run the carbon first then the phosban. Hooked up to the same pump... I have this cyno that will not go away the same as my buddies... they say it is helping with the problem and they say less glass cleanings also.