There is also significant water dilution, aeration strippers (removes volatile compounds), high capacity feeders (responds quickly to bather load so doesn't get behind in chlorine demand), microfiltration (removes dead skin cells and other particles better than sand filters), coagulation/flocculation with filtration (need slower vertical sand bed filters -- the rapid-rate horizontal sand filters just blow through coagulated particles), adsorption onto granulated activated carbon (part of the DIN 19643 method, but requires adding chlorine afterwards since it is removed in each circulation pass).
If you have biofilms, especially in the sand filter that is not uncommon in commercial/public pools, then there are biofilm inhibitor and removal products such as sphagnum moss, Aquafinesse, Spa System Flush, Ahh-Some, Multizyme (added directly to filter), etc.
None of these are needed in typical low bather-load residential pool situations, especially for outdoor pools.
There really needs to be a forum for commercial/public pool operators so that you can share your experiences and best practices, similar to what we do here at Trouble Free Pool for residential pools and spas.