I have a few questions before I go ahead a drain my pool water. Before I discovered this great site, I was ignorant and was using the hockey pucks in an automatic chlorine feeder. As a result, my CYA is around 100-110 ppm. I know the most effective and efficient way to lower the CYA is to drain some water. After reading up on draining the pool, I had some concerns because I have a vinyl liner pool. I am OK with taking the slow approach which is to dump a little then fill with fresh water and repeat as necessary to avoid damaging the vinyl liner. But my question is
1) Should I shut off the skimmer lines and drain from the main drain only so that if I reduce below the skimmer line, it does not take in air?
2) Or do I leave the skimmer open and not worry about going just below the skimmer opening?
3) Or do I just drain only enough to not go below the skimmer level (which is only about 5-6 inches)