Indeed - I would not expect you would have a problem. You use the sponges in your tanks as mechanical filtration and primary biological filtration comes from other media. (Me remembering from previous discussions we've had - please correct me if I'm wrong). I use sponges in my system as primary biological filtration. The squeezing of sponges would have much different impacts on our systems.I squeeze my sponges from filters with every cleaning...have not had a problem so far (since 2005). Strum is right, the "bacteria" once well established are pretty hardy.