Fluval 305 external canister filter in reef tank

Hi all,



i am setting up my reef tank and the tank i have has got the filter pipes coming out the bottom of the tank which connect to a fluval 305 filter

the question is do i use this filter with the media in as i have seen posts that say i dont need it as i will have live rock in the tank .....

i will be putting a uv lamp inline after the filter to circulate the water save getting an extra pump to do this

so the question is do i put media in the filter or just run it empty for the uv light

if i do put media in it then what is the best to use in it ???



Thanks