I tried em all.. Calmag has nothing to do with npk ratios though... If you need calcium (not calmag) you should use calcium.. Part 2 is 15.5-0-0.. So you're not just adding trace amounts of calcium.. Your adding a sh*t ton of nitrogen with nothing to balance it out.. I've never seen any cannabis nutrient with a npk ratio of 15-0-0.. That's just not a cannabis ratio. Neither is the 5-12-26 of part A.. That's just not balanced for cannabis.. But I wish ya success with it, like I have everyone else who's used it! I hope you kill it!Have you tried the 2 part? I am dialing the 2 part in nicely. If more cal mag is needed I just up the part B formula to give her more. If you were using the 1 part what version did you use? I know the earlier versions were lacking calmag but I thought they addressed the issue with the new formula?