I am replacing a bulk head in my sump area and need to shut the filtration system when doing this. The Bulk head needs to have a 90 deg. elbow glued in it and I was wondering how long does PVC cement need to dry before turnning filter back on. Was a bit worried about any glue vapors running through the tank. But I do not want the biology in the filter to die off either. The glue I am using in Oatley PVC Cement and Primer sold at Home Depot. Any one have any experience with plumbing repairs and how long to wait before starting system back up?