We recently put up a 28 foot around above ground Matrix resin pool with a 2 hp pump and a Sandman filtration system. We weren't having any problems originally with our pump system but have run it mostly on low on the filter cycle. We did run it a few times in high and no problems. All of a sudden if you run the pump on high in filter mode water shoots out of the backwash connector. We are totally confused as to what's wrong. Hoping you can help us. Thanks.