Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
You could do a couple of water changes including deep vacuuming the substrate, like rinsing it in the tank with a few partial fills and vacuuming it. Yes, this will destroy the 'scape, but it looks easy enough to set up again.
Then change the activated carbon daily or every couple of days. When there is a lot of stuff for it to remove it gets full pretty fast.