Can someone explain cal mag

Can anyone tell me when the best times for cal mag? Obviously with deficiencies but can it be used in mid veg for a boost because of slight stunting. Top feeding. Fox farm happy frog with bush doctor cal mag 1-0-0

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And White widow auto

What kind of water are you using if you are using tap water ph 6.0 to 6.8 you may never need cal mag.

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I’ll have to check my ph it’s well water though

With well water you have to use cal mag cause it is not already in your water.


Yeahh I had calcium deficiency in a few from last year. Didn’t happen until close to harvest so I let it go. But I know hear that these WWA also require a bit more calcium anyway so I bought it in case

I am currently growing three and never have used and may need because got something going on with plants in 3rd week of flower leaves are droopy.

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Hmm how often are you watering?

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Ever two days i cycle between water and fox farm trio

Calcium deficiencies usually happen in flowering stage same with magnesium deficiencies and iron and potassium def and Manganese deficiencies and sulphur deficiencies.but when u give ur plants cal/MAG it fixes calcium and magnesium Def’s

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I use calmag at a rate of 3ml per gallon when i use my tap water and a rate of 4-5ml pergal if distilled, ro, or rain water.

Basically use it every time you water unless you are watering with a nutrient solution that has it already.

You can’t really hurt your plant with cal-mag.


Okay that’s basically what I “wanted” to hear lol. Others say it will just flush right out mostly of soil fast as well


With well water I would add 3 to 5 ml of calmag to every gallon of water. Calmag won’t harm the plant unless u have a major overabundance of it in the medium and cause lockouts or what nots. I’d get a gallon of calmag prolly cheapest u gonna find will be botanicares calmag plus or general hydroponics calmagic either one will do u good. If u can find a dried calmag as a powder get that as any powdered or dried nutrients will last longer and go alot further than a bottle of wet nutes. A good place I found for cheaper stuff that works good is kelp4lessdotcom they have all the wet or dry ingredients needed. Good luck.


That may or may not be the case. I am on a private well in a limestone aquifer. My water is loaded with calcium and magnesium - traditional hard water. I mix in RO, dehumidified and rain water.


You will not go wrong using some Cal-Mag during flowering stage. I start it late veg, same brand 6 ml per gallon , an also use well tap water. Good luck

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Yeah I got bush doctor cal mag from fox farm

Im a hydro grower, so this may not apply exactly, but the concept is the same.

Test the ppm of your water and get a good baseline. Lets assume ppm is 0, then you want about 300 ppm of cal mag . Advanced Nutrients cal-mag will say 8ml per gallon, that much bepending on your setup is to much and will create calcium toxicity. I usually add 4ml per gallon, and if i see signs of deficency i will increase by 1ml per gallon until it stops.

If your unsure how much, get 1 gallon of water, add cal-mag in 1 ml increments and mix well, test ppm, repeat untill you hit ppm target for cal-mag “about 300” then you have your exact measurement per gal for that version of cal-mag.


Well water can actually have high amount of minerals in it already.
The earth is made of rocks and dirt after all.
What ever the ppm of your well water is. Those ppm is some kinda mineral. Exactly what it would take a water test in a lab to tell you fir sure.

Home depot actually will do it 1 time for free. They got little kits they will give you if you dont see it at the register just ask for one.
That is if you wanted to…

But if your well water is less then 150-200ppm tjen i would add 3-5ml to be safe. Good well water will have low ppm so hopefully yours is low.

But if the well water is over say 200ppm, then if it was me, I would send off a test to see what’s in it for my the sake of my consumption and it may not need cal-mag at all if thats whats creating the high tds/ppm.

I’m pretty sure lots of people use well water thats basically “mineral water” with out supplemental cal-mag but I’ve no actual experience with it…

I have Cal-mag and it was a waste of money. I have never needed it. The one time I did for s&giggles the two plants went down faster that a $2 hooker giving handjobs at a Football Convention. I had to pull the as they wouldn’t recover.

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