So we recently purchased this house with a pool and there is a PVC pipe directed straight up uncovered towards the sky. Took a look today and it was filled with standing water and green algae. I took some extra PVC pipe and made an attachment so it wouldn't blow into the pool and with pump running I opened the valve isolating it. I blew it out for 10 seconds then shut valve, soaked up some water then poured in a dose of CL. And covered pipe. Should I shock the pool and refill that piping with the new water after shocking or should the CL I added do the trick? It's the longest piping length as its furthest from pump.