greetings colleagues! I need your advice. I have a problem with brown slime algae on the roots. Im going to use physan to kill harmful microorganisms. As i know, flushing will be enough for removing physan from roots. I use rockwool and i suppose that i should soak it with physan solution, in order to suppress algae growth. I need to flush it too, or just wait? How long should i wait after using physan before adding bennies?