We have recently installed a Lemonpool LPBHL40 salt chlorinator. First time user. When we installed and plugged it in the reading was 3700. A few minutes later and it shows 0000. It's been two weeks and test strips show chlorine is low even after super chlorinate has been on. Is it broken?  How do we fix it?  I've been pouring shock into it to keep it clean so this $800 unit seems a waste of money