You won't find an auto one at the hobbyist level. There are calcium monitors out there, but they aren't that reliable from the reviews and the probes require a bunch of maintenance to work even at that level. But that's the only way to continuously monitor calcium levels. Now, there are always new products on the market.... but if you've heard it's existed past a year.... I don't believe it. You fine tune your dose with measuring calcium levels manually and adjusting CO2. When your unit is fine-tuned, you leave it be. I could be wrong.... but I haven't seen one yet.