ATA Calmag

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.

Suitable for many different kinds of vegetables, fruits and herbs like tomatoes, zucchinis, bell peppers, strawberries and cabbage etc.

• Increase in nutrient uptake
• Stronger plants
• Stimulates better quality flowers
Cultivation style soil, coco, hydro
Type of plant nutrition basic nutrients
Brand Name ATA
Suitable for in & outside
N-Value 6
P-Value 0
K-Value 0
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. 


Jutta Schoonbeek

This Camellia had a magnesium deficiency and started with adding CalMag. According to the cultivator the plant won't be much better this seasons, but in February 2020 the leafs should be beautifully green again when I increase the magnesium level of the soil. On a weekly basis I add a large dosage of CalMag in the watering can, so it receives some extra. When it rained I add some extra again because of the water that runs away. On the last photo you can see the leafs are becoming greener and also not curl anymore.

Thanks for the tip Atami!

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