I got a call this morning 2am to be exact. My down the hill backyard neighbor (Ft. Worth sheriff that works the late evening shift) calls to tell me that there is a torrent of water coming into his back yard. I get up and go to the pond and there is on 18" of water in it. I go to the pump house and shut down everything but aeration. The yard below the pond is a soggy mess. I quickly look for obvious leak points but at 2am I could not find anything. Not knowing how long the pond has been pumped down this low. I take parameter readings and all is fine. I start adding some water and Fritz ACCR. I grab an 8k gph submergible and quickly hook it to the bio-falls. I did this because I know the BD pump circuit has to be the one leaking because it pumped down nearly 2’ past the bottom of the skimmer. Fish are fine but I’m sure a bit stressed. I added enough water where I know the fish will be comfortable and allowing the bio-fall to be the only filter in operation until I find the leak later today. I have never had an issue with piping but it has to be between the BD pump and pre-filter or between as the water seems to be hold fine after i shut in the pump on that curcit. Now to find it later today. Another hard lesson learned. Time to put a low water shutdown on the pumps.