Personally i wouldnt bother setting the old gravel in bags... If you DO have an EXT. filter as well as the UGF, i think that the EXT without the UGF would be sufficient. You know the score, just go light on the feeding to help your bacteria build up. But hey, i didnt need to tell you that. Good luck, hope it goes well!Sorry I just wanted to double check. I don't have a test kit so will it still be ok to do it? Would it help if I put some of the old gravel in a zip lock bag with the bag open sitting on the bottom of the tank?