Added rowa GFO about a month and week ago is on the 60 gallon cube my phos. are at 0.2 , I figure it should be depleted by now , my question should I replace it or just keep an eye on the phosphates the tank is only going on two months . No algae thank God but I do have a large eel and two clowns in the tank which I haven't been able to take the eel out its been with me for ten years in 150 gl which I had to tear down due to moving to an apt. am getting out of topic is it necessary to keep the GFO on all the time or replace as needed

