Hesi Calmag

Product detailed description

Soft, demineralised or reverse osmosis treated water contains practically no calcium or magnesium - and without them the plant cannot build strong cell walls or photosynthesise properly.

Why calcium and magnesium are missing and what CalMag will replenish

Calcium strengthens cell walls, supports the plant structure and the transfer of signals between its parts. Magnesium is a key component of chlorophyll, and is therefore essential for photosynthesis. Together, they help the plant absorb nutrients efficiently and maintain deep green leaves. Hesi CalMag is intended for soil, coco and hydroponics, and is especially useful in modern growing systems and under powerful LED lighting, where the need for calcium and magnesium is higher.

Composition: NPK 5-0-0 (7.5 % MgO, 5.0 % CaO), also contains chelated iron and molybdenum.

Dosage

The dose depends on the hardness of the water used:

• Add CalMag to the water until you reach a conductivity (EC) of 0.4-0.5 mS/cm.
• For distilled or RO water with EC 0, the starting dose is 3-4 ml per 5 l.
• For soft tap water, use a smaller amount according to the starting EC.

It can also be dosed according to the target calcium and magnesium content: 10 ml per 50 l of water will increase the MgO content by approximately 15 mg/l (9 mg/l Mg) and CaO by 10 mg/l (7 mg/l Ca); 50 ml per 100 l of water will increase MgO by approximately 38 mg/l (23 mg/l Mg) and CaO by 25 mg/l (18 mg/l Ca). Always add CalMag to the water before base fertilisers, for example TNT Complex or Bloom Complex, or before Hesi Coco fertiliser. It can be used throughout the entire growing cycle - from cuttings through growth to flowering, by hand or with automatic irrigation.

Thanks to dosing in millilitres per tens of litres of water, even a smaller pack is enough for a large amount of prepared nutrient solution, so CalMag is a cost-effective supplement even with regular use.

Frequently asked questions

When should CalMag be used instead of a regular fertiliser?
When you water with soft, demineralised or RO water, or when growing in coco or under strong LED lighting.

In what order should CalMag be added to the water?
First CalMag, then the base fertilisers in the Hesi range.

Can CalMag be used throughout the entire growing cycle?
Yes, from cuttings through growth to flowering.

Exact dosing for individual ranges can be found in the HESI dosing table.