Pool will not hold chlorine level when set on automatic regardless of the ORP set point. When set on % pool will hold and even generate chlorine. Pool construction company has been attempting for 2 months to rectify but has thus far failed. Hayward suggested lowering the CYA from 60 to 25 by partial drain down. Tested sense and dispense. Replaced SWG. shocked several times and would hold on percentage but not on any ORP setting. FCL 5.70 TCL 5.69 PH 7.4 ALK 72 CH 131 SALT 3100. Set ORP on 650Mv and chlorine drops to 4, next day 2, following day 1, then zero. Hayward rep tests system and water and states that it is OK. Pool construction company says next they will try massive shock. Several smaller shocks did help but did not solve problem. Pool showed some green color when first filled but they fixed it somehow in short order. Within a week scale formed and they dumped in 4 gal MA and that was solved. Next pool went on free service for aprox 10 weeks. Purchased a good test kit and started tracking chemistry. When chlorine began dropping out I asked pool service people and they stated it tested OK. When free service ended I went to pool store and they wanted me to super chlorinate then add salt, sodium bicarbonate,CYA. So I tried to get chlorine up with super chlorination as pool began clouding up, then I called the construction company and they began their 2 month attempt to have the pool operate on automatic. Pool is now on 90% and chlorine has risen from 1 to 4. Now they say they want to shock again. (I am unclear if they ever shocked my pool hard enough or long enough in the past, but the water looks good) I said to them that I am getting frustrated and am about ready to drain the pool. They liked that idea, but perhaps I should allow them to do a massive prolonged shock to oxidize any possible organic organism before I pay to drain refill and rebalance.