This APC Pool Pal Chlorinator and SPP Liquimate Chlorinator operate in a different way than Hasa's The Liquidator. These first two units pump (via lower pressure) concentrated chlorine directly from a large jug into the pump water stream. The latter unit (The Liquidator) works by just diverting a small amount of pool water flow over a bed of concentrated chlorine where the denser chlorine stays on the bottom with some chlorine diffusing into the water above. Apparently, much of the extra salt in bleach and chlorinating liquid remains in the jug and the jug must be thoroughly cleaned (dilute acid-washed) when there is calcium carbonate buildup. And, of course, there's another option which is using a peristaltic pump.

See this thread for info on several of the options and this thread for info on The Liquidator and this thread and this thread for info on peristaltic pumps.

Looks like so far The Liquidator is easy to install and people are so far happy with it, BUT it requires thorough cleaning every some number of months. The Liquimate doesn't work well. The peristaltic pumps work but may be more complicated to install or more expensive. It seems that all of these solutions have fixed metering, but then again that's the way an SWG works as well, so adjustment of chlorine flow to get consistent levels is an issue for all of these systems. For outdoor pools, the sunlight breakdown of chlorine self-limits the maximum FC level; for indoor pools, getting very high FC levels would be easy to do so monitoring is important.

Richard