So I've had the Dastaco ExtremA4 running for about a week now and it did take a few days to dial in. I enjoyed ph of 8.3 to 8.5 when I was dosing two part with a kalk reactor. Now with the Kalk reactor and CO2 scrubber I'm down to 8 to 8.1. After 2 days of running it I came down to the basement and my CO2 bottle was empty. I must have had a leak from the regulator to the tank. I changed out the tank enusred no leaks, and recalibrated the reactor. My tank is running solid at a DKH of 9.8. Corals and clams are doing beautifully. Once you get this thing dialed in, it is set it and forget it. Totally worth the investment. I'm all about automation and simplifying things when I can. I prefer to spend my time in front of the main display instead of down in the lab tinkering with 2 part and dosing pumps etc. Between my auto water change, the Dastaco and my apex controller, I definitely feel that it has freed me up to enjoy the tank inhabitants more. Now only if we can get that Trident out to the stores!