Did I mention the PROMIX product was expensive? About $20 for "1.6 kilo" tub. The weight is less relevant since the product is doled out by volume for dilution - volume was nowhere near the container size (on account of "settling"). True that a small scoop makes a gallon (5 L) of liquid but I am using 5 or 6 scoops to feed 24 plants in the greenhouse once a week.... and more for the dozen outdoors.

Bower, I have been using the 20-8-8 Pro Mix, as I couldn't find the other one. It is expensive. It's been good, but my in ground plants really like it. Personally I like Miracle Gro 18-18-21 with micronutrients for the water soluble. It has magnesium in it which is hard to find as you know in the water soluble and my plants are mostly grown in Pro Mix. I am also a fan of the Pro Mix granular 9-3-6 slo release with micronutrients. It has worked well for me. It has calcium and magnesium as well. So I personally use both - alternately. When planting I use the granular to start, then sprinkle on half way through the season.
This year I also bought some Cal-Mag from a hydroponic store and so far no BER. Not sure if that made a difference or I was more conscientious of watering - although it has been a rainy summer so I haven't had to water much.
By the way, I didn't notice the warning on the Pro Mix container. Yikes. Well it certainly hasn't been too dry here. And today feels like a fall day.

Correction - it's the MG 9-4-12 Miracle-Gro® Shake 'N Feed® Tomato, Fruits & Vegetables Continuous Release Plant Food Plus Calcium. I think it's great. JMO

That miracle grow sounds great. It has nice amounts of Ca and Mg, I thought it would be a new formula, but I see reviews from 2013. Surprised I haven't heard about it around here. It's cheaper and stronger than TTF and it is complete.

Zipcode, I have had very good results with both Miracle Gro formulas. The 9-4-12 granular mix is not that available here either. You can order it on Amazon, I believe. The water soluble 18-18-21 is also on Amazon and also not everyone carries it. I have had a hard time ordering TTF so have given up and will stick to these and a few Canadian based companies. At least MG provides everything.