Well if he diddnt get demolished then id say maybe only 2 days, or do a water change. Yes I know I havent been here long but I have experience in this, mine got demolished, completely, except for the mouth and a single tentacle. I rean carbon for a week and a half, did a 50% water change aggggggggg!!!!! It sucks when that happens. Cover your intake with filter pad when he is moving.