We have a newly restored (plaster finish) in ground 8000 gallon pool with a new ionizer to achieve a minimum maintenance pool. After 2 months of surface leeching break-in period struggle to keep the pH and TA right, we were told by a biochemist that a little chlorine to supplement the ionization treatment against the algae and bacteria would help keep the pH right. We now have a "vacation tablet canister" plumbed into the return with less than 1 ppm FC. It appears to help keep things in balance. Does anyone else have such an ionizer-chlorine hybrid system with a thought on how much FC is right?