We just opened our pool a week ago and have no flow at the returns. To troubleshoot, we disconnected returns line and put a temporary line from the chlorinator straight into the pool, and the flow is fine. Tried to unclog the return line with the drain king going both ways - first from return to the pump, then the opposite and got a little flow, but still not enough to get the returns to circulate the water. Our pool guy keeps telling us that it's a "pinched" line somewhere and pursuing us to dig. We have no trees in the backyard, thus no roots to jam the line. Can the line get pinched/collapsed by itself? There seems to be no water level loss (except for natural evaporation). We also tried to snake the line, the snake goes in about 7 feet from both ends and stops dead, I guess somewhere at the 90 degrees joint. What else could we do to diagnose the problem - I'd really hate to dig and bust the concrete patio just to find out it was a stupid hair clog!