This is a phosphate filter pad for fresh and saltwater. It does not need water to be forced through it. All water needs to do is run over it. This simple and easy to use pad will remove all the diluted phosphates from your tank within 48 hours. When process has been completed simply remove the pad and discard. Can not be regenerated. It is non-toxic and contains no chemicals that would make it environmentally unsafe. It is safe for reef and plants.