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Calmag Agent 5 Litre Canna

Calmag Agent 5 Litre Canna

  • $169.00

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With varying water quality throughout New Zealand and more and more people using Reversed Osmosis water on COCO substrates, Canna have created a Calmag solution for your soft water problems.

There is a complex chemistry in your water going on when using soft water or Reverse Osmosis (R.O.) water in combination with a Coco substrate within the divalent ions such as Calcium and Magnesium. By controlling this issue, carefully and by addressing the need correctly, control of the problems this brings is achieved without the over application of Calcium and the resulting decrease in certain nutrient ions availability to the plant, such as Potassium.

Canna Calmag is a water conditioner and pH stabilizer designed for use when using a Coco substrate. The Calmag agent ensures a balanced amount of calcium and magnesium specially designed to add to your nutrients. This product will increase the EC value of the water you use, stabilizing the water for your plant to feed on. It makes water harder and will create the best base water for your plant to be able to take in all the nutrients it needs, to grow healthy and strong on a coco substrate.


  • Perfected for use on Coco substrate 
  • Stabilizing the pH of your water
  • Fewer deficiencies in Calcium and Magnesium 
  • Enhanced nutrient uptake
  • Stronger plants
  • Stimulates better quality flowers
  • Increases the EC of your water

Soft or R.O. water

  • Mix your desired nutrients in the tank first
  • Mix in the additives to be used such as CANNABOOSTRHIZOTONICCANNAZYM and, or PK13/14
  • Add Canna Calmag to the nutrient mix as last following these guidelines:
  1. Dosage: Depending on water quality, softness and target plant, use 5 - 10 ml / 10 litres.
  2. Keep in mind that a stable pH is also temperature dependent.
  3. The nutrient solution can be applied directly after mixing but wait 24-48 hours before doing any pH adjustment to allow correct buffering of your solution.


  • Be careful when using a pH Up (+) as Canna Calmag Agent will first drop in pH and rise over the course of the next 24–48 hours

For more information about water quality and when to use CANNA CALMAG Agent, see the CALMAG articles on the CANNA website.

What is the difference between soft/hard and/or bad water and what can you do about it?

We have divided water into four different types:

  1. soft water
  2. normal water
  3. hard water
  4. bad water

Soft water has an EC level of below 0.4. With CANNA CALMAG AGENT you can raise your EC level to 0.4.

Normal water has an EC level between 0.4 and 0.7. It contains calcium, magnesium and bicarbonate to stabilize the pH. All CANNA products are designed to work best with this type of water.

Hard water (EC>0.8) contains more calcium and magnesium than the plant can handle. When you’re growing plants, the best way to treat this kind of water is to use a reverse osmosis filter and then mix your hard water with the R.O. water, until you reach an EC level of 0.4. Or, more easily, you can use 100% R.O. water and then use CANNA CALMAG AGENT to raise your EC level to 0.4.

Bad water (EC>0.8) contains mainly sodium and chloride. These two elements block the uptake of nutrients and can even become toxic to your plants. With a reverse osmosis filter, you can remove both these elements. But making a mixture of R.O. water and bad water will not bring in enough calcium and magnesium, only bicarbonate to stabilize the pH. Make a mixture of R.O water with the bad water until you reach an EC of 0.2 and then add CANNA CALMAG AGENT to this water until you reach an EC level of 0.4, or use 100% R.O. water in combination with CANNA CALMAG AGENT until you reach EC level 0.4

How can you test the difference between hard water and bad water?

The easiest and best way to find out, is to contact your local water supplier. They should be able to provide you with an overview of the ions in your tap water. An other option is to have your water analyzed by an official laboratory.

You can also test the water yourself using an EC meter and 2 small tests based on colour indication. First, measure the EC to be sure it is not SOFT or NORMAL water:

  • EC 0.0–0.3: the water is Soft
  • EC 0.4–0.7: the water is Normal

If the EC >0.8, continue with the test (to determine which elements contribute to the EC measured).

  • A testing kit can be bought in an aquatic shop.
  • Buy the kH and the gH bottles.
  • If the gH (Gesamthärte = general hardness) < 8 (drops), the water is BAD, e.g. the EC consists mainly of sodium, chloride etc. not calcium and/or magnesium.

If the gH is > 8 continue with the TEST.

  • kH (Carbonat-Härte = carbonate hardness) < 8, the water is also BAD, e.g. the water is not sufficiently pH buffered
  • kH > 8, the water is HARD