This is why I microdose with every watering. For example, I can feed with Mn sulfate and send my soil to get tested and it will still show low in Mn. It's easy to want to over do it, but then you will cause problems especially if you adding it to a plant. You can be more heavy handed if you are not planted in the soil, but adding too much will cause problems. I never had luck using Big-6 and TM-7, but I think that has something to do with the application rates. On established plants, you don't really want to do hit them hard. i don't exactly know what it does, but the plants don't respond very well. They will look like crap and recover later and look better than ever, but there is a 2 week window where everything looks like crap. I'm talking about 6grams per gallon of Big-6 BTW. I've had much better luck with 6 grams of Mn sulfate alone, but I'm still hesitant to go that high unless I know for sure that my plants are yellowing from Mn def. It's a fucking tricky situation, it really is. I had to hire a professional to help me figure it out. Thankfully, I make my own compost and my problems can be recreated on every compost batch. So, I have a good idea of what my soil needs now. However, there is still always one other micronutrient that is out of balance. It's usually Zn or B...