Botanicare Cal-Mag Plus


Every grower needs cal-mag plus! This is the one trusted formula that will give your plants what they need: a balance and an optimized ratio of calcium, magnesium and iron. These 3 ingredients are quite literally mission critical for your all your plants growing stages. Use 300 PPM when using RO water.

SKU: SKU4 Category:

A custom-designed, highly-beneficial calcium, magnesium, iron, and trace mineral plant nutrient supplement that helps with calcium, magnesium, and iron deficiencies in nutrient fertilizer programs. Cal Mag Plus also helps replenish calcium levels as it is naturally depleted in coco coir fiber media applications.

Cal-Mag Plus provides a precise balance and optimal ratios of the calcium, magnesium, and iron that are critical throughout all stages of growth, especially in heavily fruiting plants and fast blooming annuals. Cal-Mag Plus is fortified with a proprietary blend of select trace minerals to help maximize yields in fruiting and flowering plant varieties, prevent blossom end rot in tomatoes and peppers, and reduce tip burn in lettuce. When used in combination with nutrient solutions Cal-Mag Plus functions as a catalyst to increase the uptake of essential minerals.

Cal-Mag Plus contains: calcium, magnesium, iron, boron, zinc, manganese, molybdenum, copper, cobalt, iodine, beneficial vitamins, twenty essential amino acids and select botanical plant extracts.

Cal Mag Plus Product Information (PDF)

Cal Mag Plus Feed Sheet (PDF)

Cal Mag Plus Safety Data Sheet (SDS) (PDF)


ARNY:We’re back with another installment of “John in 60 Seconds” to discuss Cal-Mag. You’ve got 60 seconds to answer a few of my questions about Cal-Mag; you ready, John?


JOHN:Let’s do this!


ARNY:All right! What is Cal-Mag?


ARNY:Cal-Mag is a calcium-magnesium-iron additive or supplement that most people use at almost every grow.


JOHN:What do you use it for?


ARNY:A lot of nutrients these days … A lot of plants need more calcium and magnesium, and certain nutrients can’t give it to them in the amounts that they need, so you would just add it in as a supplement.


JOHN:Why? Why are we adding it back in?


ARNY:Some people have RO water, some people have Coco Coir that they’re growing in, and both those things strip out all the calcium and magnesium. You want to make sure that you have enough calcium and magnesium; you will see deficiencies in your plant.


JOHN:What kinds of deficiencies? If you could share a couple examples?


ARNY:Sometimes you’ll see browning of the leaves, you’ll see some curling … You’ll see just discoloration …


JOHN:What’s a rookie mistake that people do, when using Cal-Mag?


ARNY:I think the biggest mistake is they don’t use enough of it. They think just a little bit is enough, but you actually need to see what your water is before and after you add Cal-Mag.


JOHN:Are there any instruments or tools that we could be using to test these things?


ARNY:You’d definitely be using a parts-per-million meter … Bluelab makes a great one that’s really easy to use. They have actually a few variations that you can use.


JOHN:Great! Now it’s time for a “Pro Tip” … What could you share with our audience, in your experience, as a “Pro Tip”?


ARNY:Whenever you’re using RO water, I would definitely recommend 300 parts per million of Cal-Mag before you add anything else in.


Average Rating


(2 Reviews)
5 Star
4 Star
3 Star
2 Star
1 Star
Submit your review

2 Reviews For This Product

  1. 02

    by George Kramvis

    Excellent product. I did not have any blossom end rot on any tomatoes, eggplants, zucchini, cucumbers and chilies. Also crops were abundant.
    Previous years struggled with other calcium products. Very easy to use.
    Combined it with molasses and liquid fish fertilizer.

  2. 02

    by Robert Cazinha-Nakamura

    I never have any Cal Mag problems

Botanicare Cal-Mag Plus

Botanicare Cal-Mag Plus


Add to Cart