I'm over a month into a switch from the original 3-part Essentials to the Essentials Pro 2-part. I still can't get anything stable in the tank. Alk is swinging 0.5 one way, then another, all on the same dose. My calcium dropped from 430 to 350 within a week of switching, and has taken nearly double the dose of alk just to keep stable after I corrected it with BRS calcium chloride. It's been a nightmare, and I'm losing corals and nothing looks anywhere near as good as it did a month ago. On the original 3-part essentials, my parameters were rock solid at 8 dkh and 430 calcium dosing about 330ml of solution per day in my 190g volume tank. The amount I was dosing was getting pretty annoying to keep up with, so I was excited to move to the Pro which is supposed to be 1/5 the volume dosed compared to the original. I started out at 60ml, and watched my alk jump 0.6 dkh in less than a day. I dropped that down to 30, and matched the calcium dose and was getting high 7 to low 8 alk readings for a week or 2, until I started noticing coral health issues. I then checked calcium (which had never moved) and it was down to 350!! By the time I got this corrected, most of my coral had browned out and I have a few that started to STN. I've been battling the dosing amounts for weeks now, trying to find stability, and can't. I'm down to 24ml of Pro per day of Alk, and it will sometimes go up 0.2 or down 0.2, with no real pattern. This is getting measured by an Alkatronic pretty regularly. I anyone else having these issues? I know a buddy of mine also went to Essentials Pro and is having tons of problems as well, but wanted to see if it was a common problem, or something related to my system that just doesn't work with it. I would have expected the transition from Essentials to Essentials Pro to be smooth and easy....instead it's causing tons of headaches.