I am going to treat one of my tanks for parasites and am wondering if i have to remove the carbon from my filter. I have a fluval104 that I quit changing the carbon on 6 months ago. I left the carbon in for added biological filtration and did not want to take the filter apart unless I have to. I thought that being 6 months old the carbon would no longer be active and I could leave it in. I clean all the filter media every 6 weeks or when the flow decreases and it will not need doing for a few more weeks. Thanks in advance for any help .