Hi with the announcement of the P4 we also mentioned that Alkalinity and measurement of other parameters (e.g. Ca) are coming soon. Personally I didn't expect that much of feedback and interest in these planned new features for the ProfiLux, actually I wasn't aware that this is something special since the automated measuring of Alkalinity and Calcium is standard in laborities, nutrient production and public water supply for decades ... nothing spectacular in my eyes. However, we didn't want to just start a hype with some vage announcements, actually I planned to annouce more facts as soon as details like release date and prices are clear. So now, as the "cat is out of the bag" (I hope this phrase makes sense in English) I want to give you some more information here. Q: What is the current state of measuring Alk and Ca with a ProfiLux? A: GHL has been working on continous automatic alk monitoring for alsmost 2 years now. The prototypes are running reliably meanwhile. The next step is to design an affordable product for the "mass-production". Ca was easier, works also, but the price is here still the issue. Q: Will this work for ProfiLux 4 only? A: No - Alk and Ca measuremtn will be possible with ProfiLux 4 AND ProfiLux 3 Q: Can I control or just measure? A: As with all probes a ProfiLux can use the readings to start actions like switching sockets (pumps, solenoids), dosers, etc. It is up to you if you only check the values and act on your own or if you let Profilux handle that. Q: Release date and price? A: Sorry, still working on it. Don't want to disappoint if we can't keep the promises. But definetely in 2017. Q: Can we see some videos? A: Later, not in this phase of development. Just don't want to be copied or start debates.