ok i have a quick question. i was looking in my 405 and i know it has the different areas for different stuff. do i only add 1 polishing pad or can i add 2 and also the same with teh carbon can i put more then 1 in there. i was also told that the prefilter things go in the last bin in the filter. could some of you guy that run the 405 explain to me how you have your stuff in the filter. i just want to make sure that everything is in the right place. thanks