Question about Jacks and cal-mag

Is it necessary to add cal-mag to Jacks? I’m switching from Fox Farm trio to Jacks just wondering! @Bobbydigital @Budz @Covertgrower @dbrn32 @Myfriendis410 @MeEasy


Negative. Cal nitrate and magnesium sulphate are two of the three components.


It’s has it in there but you can’t go wrong by adding some more. (I stand corrected it’s one of the 3 parts in jacks 1 2 3 not a part of their actual mix.

Gh maxi series has calcium nitrate and magnesium sulfate in their mix, I add plenty more to that as well

With Jack’s I’ve actually had to reduce the cal nitrate on a few plants. One plant I’ve had to raise the magnesium sulphate. So it’s adjustable since each component is already separated.


What strains did you have to adjust? My current grow is GGlue Green Crack and Chemdawg. PharmerBob just suggested i should sill add some is that correct? @PharmerBob @Bobbydigital

I had issues with a round of apple pie, they clawed & withered away faster then I expected and before I knew it I was swapping crops.

Yes but be mindful of what your adding, maybe keep track of the data daily as you go for reference, if your not already of course

It’s already 2 parts of the 3 part solution. If you need more calcium, add more calcium. If you need more magnesium, add more magnesium. Think it was jack herer and GDP that I had to reduce the calcium. Gold leaf and I believe another one I had to increase the magnesium. Can’t remember at the moment.


Assuming good root development and proper watering practices, no additional C or Mg needs to be added. As stated; if you see a calcium def, up Part B. If mag def add more Epsom (magnesium sulfate).

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Thanks for the input guys i appreciate it! @Bobbydigital @Myfriendis410 @PharmerBob

What they mean is, you can increase calcium by upping amount of calcium nitrate or magnesium by increasing the amount of magnesium sulfate. So there is no need for you to go out buy a separate product that applies both.


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What made you switch?

I always thought of calcium nitrate to be part B, no?


Always had difficulty with keeping Ph under control. Didn’t listen to the advice to only do about 1/2 of what fox farm recommended. Plus nute burn.

Well of course it is! Brainfart haha. Thanks for catching! I’ll edit the answer so it doesn’t confuse anyone further.

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