CANNA CalMag Agent bottles in multiple sizes on a white background

CANNA CalMag Agent

Calcium + magnesium support
For soft, RO or demineralised water
Supplement only

A water-correction supplement for growers using soft, purified or RO water with CANNA nutrients. CANNA CalMag Agent helps bring calcium, magnesium and base EC into a better range before the main feed is added. Especially good for coco, hydro and semi-hydro plants.

Quick facts

Type: CalMag supplement
Substrates: Soil / potting mix, Coco, Hydro, Passive semi-hydro, and LECA
Dosage: Add to EC 0.4-0.5
Frequency: As needed for soft water
Skill level: Intermediate
pH/EC: Recommended

€14,25

VAT included · plus

Please note: Most fertilizers ship separately from plants. A separate shipping fee may apply, and the final cost is calculated at checkout by order weight. Free shipping does not apply.

Size:

1 L 5 L

Variant

4.6/5 store rating · 20,000+ customers served

Tracked shipping

CANNA CalMag Agent is used before the main nutrient when very soft, RO or rain water needs mineral correction. It prepares the water rather than replacing the base fertilizer.

For soft water and inert media

The product is relevant for RO water, very soft tap water, coco, LECA and strong grow-light conditions. It supports the feeding plan; it does not replace it.

Use with a real reason

This is not the first bottle for someone who simply wants plant food. Start with a complete fertilizer, then add CalMag Agent when water or substrate conditions justify it.

Is it right for your plant?

Substrate Soil / potting mixCocoHydroPassive semi-hydroLECA
Best for Coco-grown plantsSemi-hydro plantsWater-grown plantsPlants under grow lights
Helps with Water correctionMineral balanceRegular feeding
Choose another product for complete base feedinghard-water correction

CANNA CalMag Agent fits hydro, coco and semi-hydro users whose starting water lacks calcium and magnesium. Relevant for fast-growing foliage plants under LED lights or in coco-heavy media.

Not every tap-water household needs extra CalMag, especially in hard-water areas.

What's inside:

NPK Ratio: No NPK / Ca-Mg water conditioner, concentrated Ca:Mg ratio 3:1
Nutrient basis: Calcium-magnesium water conditioner

CANNA CalMag Agent is a water-conditioning supplement for calcium and magnesium support. It is especially relevant before feeding with soft, RO or rain water.

There is no standard NPK ratio; the product is described as a concentrated Ca:Mg conditioner with a 3:1 ratio. It prepares the water background; it is not the complete feed.

How to use it

Add CANNA CalMag Agent it to soft or RO water before the main fertilizer, usually around 0.1-0.5 ml/L to reach EC 0.4. For visible deficiency correction, stronger temporary use around 1-2 ml/L may be needed.

After water correction, mix the base nutrient and check the final pH/EC.

➜ A few notes before measuring, mixing or applying :

Use water hardness or EC readings; plant symptoms alone are unreliable. Too much CalMag can interfere with potassium and other nutrients.

Mix it into water first and avoid direct contact with undiluted A+B nutrients.

CANNA CalMag Agent

€14,25

Frequently Asked Questions about CANNA CalMag Agent

When do I need CANNA CalMag Agent?

Use it when your starting water is very soft, RO or low in calcium and magnesium. It is especially relevant for coco, hydro, semi-hydro and fast-growing plants under strong lights.

Is CANNA CalMag Agent a complete fertilizer?

No. It corrects calcium and magnesium levels in the water, but it does not replace a proper base fertilizer.

How should I add CANNA CalMag Agent?

Add it to the water before the main fertilizer, then mix the base nutrient and check the final pH and EC. Do not guess if you can check your water hardness or EC.

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