Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Do not change media. Clean and reuse. There are a lot of beneficial bacteria living on the sponges, and pretty much all the surfaces in the filter and in the tank. Clean the sponges in water that has been removed from the tank for a water change.
Do as thorough a vacuum as you can, removing as much fallen debris as possible. Do more water changes, and make sure the dechlorinator will lock up ammonia.
For a few days, quit feeding.