Epsom salts: I have a couple questions

I have some questions regarding Epsom salts, as I have never used them myself. Here we go:

  1. can you use the scented salts to add to watering?
  2. do they differ from Cal-Mag (the magnesium portion, obv) in any way other than providing sulfur?
  3. what are the advantages/ disadvantages of using them vs using Cal-Mag?
  4. should they be used if there is NO nutrient lockout or deficiency?
  5. what is the most efficient way to add them? (feed water, top feeding, foliar spray)

Thanks again for all the quick, helpful responses I’ve been getting since my first day here. I’m very new to the forum, but I think I’m gonna stay as long as you’ll have me! Cheers and Stay Lit :fire:!!!

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No don’t use scented salts use pure Epson salt

No. Not recommend. Never tried it though.

Epsom salt does not have any calcium in it.

You’re less likely to see a magnesium deficiency, as it adds more than just cal mag in it. Probably depends on the brand, and their proprietary ratios, but I saw 30% calcium but less magnesium.
I use Jacks Nutrients 321, and it’s added into the recipe.

I recommend using them as a good preventative, I’ve seen most of my issues happen suddenly, and by the time I see them, the plant is already behind on nutrients.

Adding to the soil is the best way. I mix mine with my nutrient feeds.


OK I know I only answered one question lol I use it part of my everyday feeding but im using jacks 321 formula so it depends on ur nutrients. Best way to add it is to ur feed water dissolve it in a glass bowl with some warm water then add to nutrient mix.

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Most of the time in flower you see magnesium deficiencies as opposed to calcium deficiencies. Epsom is great for targeting that without adding calcium and nitrogen that may not be needed.


@Killadruid that’s the gut feeling I got and the reason I asked. Thanks a ton! :pray:t3:

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@Covertgrower Very detailed response! Thanks for the info :pray:t3:

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@BobbyDigital Ahhhh…good point. Great answer :+1:t3::pray:t3:

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Another thing to build on top of bobbydigitals response, when you have good quality LED lighting, you’re more likely to see calcium and magnesium deficiencies, and should add it to your schedule anyways.


@Covertgrower Wow! Is that because they use more of it during photosynthesis? Or does it become more mobile?

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I think it’s the higher PPFD ratings that LED puts out. Just my opinion here.

@Covertgrower :+1:t3:

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Are u in coco?

I’m in both soil and coco. Not sure who that was directed at. Lol


What is the amount of epsom salt per gallon of water?

@Covertgrower… Love your new icon/Pic.

1.2g per gallon. Thanks! I can’t claim credit. But it’s pretty cool.

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