ATA CalMag is a supplement with the aim to provide calcium and magnesium to the plant if there is too little in the nutrient water. Although hard tap water in most countries contains ample calcium and magnesium, a CalMag supplement may be advisable in some cases. Especially when the grower uses soft tap water, such as in large parts of the United Kingdom or osmosis water (demineralised) water, the use of CalMag is even a must for the plant.

The use of ATA CalMag is also recommended when growing on a coconut substrate. Growing on coco has a higher risk of calcium and magnesium deficiencies than cultivation on soil or hydro. 

Both calcium and magnesium are secondary elements, which means that they are essential for healthy plant development. The only difference with the primary elements (N-P-K) is that they are needed in smaller quantities.

• Increase in nutrient uptake

• Stronger plants

• Stimulates better quality flowers


Type of plant nutritionbasic nutrientsCultivation stylesoil, coco, hydroBrand NameATASuitable forin & outsideN-Value6P-Value0K-Value0


Add 0.1-1 ml Calmag per litre of nutrient solution.

Grow tips 

Use Calmag to enrich water that is poor in calcium and magnesium or as an additive to your regular fertilizer solution. Use water at room temperature (21 °C) for an optimal result. 


250ML 1L 5L

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