This is our second year having a pool so I don't have a lot of knowledge when it comes to pool maintenance. I have a simple salt pool and I was not able to keep chlorine in the pool all summer. We live in Michigan so its about time to winterize the pool. My local pool store ended up running a chlorine demand test last weekend and told me we needed to add 8 gallons of chlorine to our pool in order to break through. So I did that and waited 24 hours and tested from home with my strips. It showed we have 0 chlorine in our pool. I brought in a sample to the pool store and they told me to add 3 more gallons without doing another chlorine demand test and add the winterizing kit and call it good for this year. I want to get a second opinion because I don't want to close my pool and have even more problems come spring when it's time to open. What should I do?