I have read up on their product and come to the conclusion, it's just how they use them . I have seen KZ stones and AF stones and they look no different .
U are advised to shake them up every now and then to slough off the bacteria . It's just not as an aggressive method as Zeo .
Awesome thanks so much for the response. So I am now one week into tank cycle and using no pro and Probio S. When should I start seeingseeing. Bacteria on the stones?