Haha thanks. The bag is some mature k1 media I was using to help keep bacteria colony up after shutting down one of the pumps for a few hours. Had to do some maintenance couple weeks ago and just hung that bag above the aerated bottom drain as a precaution. Haven't gotten around to taking it out yet.
Gotcha that was my second guess but I thought it was maybe some new pumice lol. In any case looks like you have a pretty efficient filtration set up going.
