Carbon pads are just annoying!!! They remove toxins yes but then starve filters on nuterants that's much needed to feed the beneficial bacteria.
So watch to ammonia levels for the next 5 days, as you many need to do some water changes.
The rest of the media you never need to replace, other then the filter floss.
Any ceramic's or sponges should be cleaned once a month in a bucked with tank water and then put back in the filter and fresh filter floss added.