British Organic Bio Organic CalMag 1 Litre

Organic, soluble Calcium with ample levels of Magnesium

Getting a soluble form of calcium and magnesium for organic growing is tough. A lot of the products on sale for conventional growers are based on synthetic chemicals and chelates. Plus, most of the organic calcium products are insoluble powders (e.g. lime and gypsum). Organic Cal-Mag utilizes a a unique manufacturing process to combine organically approved ingredients into one fully soluble liquid product.

Why does Organic Cal-Mag have a pink hue?
Organic sources of calcium and magnesium always have a pink colour (see the Dolomite Mountains in Italy as a great example!). Organic Cal-Mag products that are white in colour invariably contain no magnesium. This can lead to chlorosis due to a lack of magnesium in the product. Furthermore, any calcium in the product then goes on to interfere with the uptake and use of magnesium from the base feed. For this reason, we ensure that Organic Cal-Mag has ample levels of magnesium in it, thus giving the pink hue.

Why such a low dose rate?
We use only the finest organic starting materials and provide a true analysis of the actual nutritional content. Give the bottle a shake and see how thick and viscous the product; it is packed full of calcium and magnesium. As a result, you do not need to apply much to get massive gains in yield and quality in your crop.


Add to the nutrient solution as follows:

For hard water areas apply at 0.5ml per litre of water.

For soft water areas or for growing in coco apply at 1ml per litre.

Also, if you are growing in coco its a great idea to pre drench the substrate with a solution of calmag, 1ml per litre, before potting the plants. This will help to avoid nutrient deficiencies later on.


Microbial activity(beneficial bacteria and fungi) is a key part of organic gardening, to avoid harming the soil life we avoid using fresh tap water due to the presence of chlorine. We can use filtered water, leave tap water to stand for 24 hours or a simple solution is to apply Ecothrive Neutralise to instantly dechlorinate tap water.


  • Produced in the UK
  • Organic, soluble calcium and magnesium
  • Highly concentrated
  • Perfect for coco growers
Weight N/A

1 Litre



Call Us