Hello guys! I am new to the pool world and I have been having trouble ever since I started. I have the Intex SWG. I don't think it is working like it should. I have read how the system works and it is my understanding that it reads the currents between the plates to tell who much salt is in your pool. My pool started to turn green and I went and had my water tested. They said I was low in salt but my unit never had a low salt alarm. I also noticed that one of my plates is copper colored and the other two is black. Is this normal?