So…I’m running GFO. This thing came with sponges which I know people use for carbon, but for the life of me I can’t find instructions on this reactor or photos with sponges.
Do I even use these? Do I put one on the top, the bottom? Both?
Bonus points if anyone can tell me what the black pieces are under the sponge.

Do I even use these? Do I put one on the top, the bottom? Both?
Bonus points if anyone can tell me what the black pieces are under the sponge.


