Do you personally ever have the need to use it? You kill it with Tomatoe feed right? (Bad memory)
I could see it used at that rate for a top-dressing once in beginning of Veg/flower & once half way through or end of veg.
Probably would be good as an amendment to a whole 5+ gall. Pott of soil or media before transplanting a plant with fully established roots.
I just started using epsom last year, so not a Pro. On using it by any means. Although these portions i listed have contributed to kicking LedDefficiency in the balls for me.
Still figuring this shit out myself.
Went through a good 2 yrs of lock-out n everything else before dialing to where I'm at now. Could have been allot less time had personal issues not came first, but that is life.
I just sprinkle the crystals into bottom of soil before transplanting. I don't drench soil or foliar spray with it.
I just did the ec ppm test.
1 tablespoon of Epsom salts in about a pint, ~ 0.5l of warm water, stirred it until dissolved.
Put the mixture into watering can and filled it up ~ 9l, around 1.98 mperial gallons, gave it a good mix.
The ec reading was 1.1
Ppm 500 was~ 550
Ppm 700 was ~ 750
Just for curiosity I went to the Westlab company's website for more info - that's the brand I use
And found this.....
Try mixing 2 cups of Epsom salt, 1 gallon of white vinegar, and ¼ cup gentle dish washing up liquid as weed killer.
westlabsalts.co.uk
They reccomend 1 tablespoon per gallon, twice the strength I tested.
As a side note
Looking at cal mag products it seems they all have different levels of nutrients,
For example Ionic cal mag plus has 3.8 total Nitrogen, Calcium 5.6 magnesium 4.01
Botanicare cal mag total N 2, Calcium 3.2, Magnesium 1.2
Shotgun cal mag N 2.6 Calcium 3.2 Magnesium 1.2
Plus the diffent types of calcium used for plants.
So If I added Ionic cal mag plus to Tomatorite 4N 3P 8K the npk ratio would change to 7.8N 3P 8K , more like a vegging nute than a flowering nute I'd say.
Seems it's Not Just a case of " I've got a Cal Mag problem, I know, I'll just buck in some cal mag to sort it out.
Adding a Calcium only product seems a good way to fix a Calcium problem and adding Magnesium on its own will sort out the mag problem.
Chempak fertiliser Co. over here does a Calcium packet but I cant I can't find it's breakdown analysis just now.