In StockCanna Calmag Agent
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Description
Canna Calmag Agent is a buffering additive that is designed to be added to soft or RO water to make your tap water more suitable for hydroponic use.
If you live in a soft water area (if the EC of your tap water is less than 0.4) then Calmag Agent will help you bring your water up to what Canna consider normal, or optimal, for use with their products. They state that their UK nutrients are designed to be used with water that has a base EC of 0.4 - 0.7 as this is the background EC range that will give the best results when using their nutrients.
Canna Calmag can also be used to give RO water a decent buffer level and bring the water back up to a point where using the standard Canna Nutrients are possible, without this buffering the pH of the solution will be very hard to control.
Canna make some of the best nutrients on the market, getting your base water into the zone that they formulate their nutrients to work best with makes a lot of sense. If you have soft water or use RO water and also use Canna Nutrients, this product is a no-brainer.
Key facts
| Type | Calcium and magnesium additive that buffers soft or RO water |
|---|---|
| For | Soft tap water (EC under 0.4) and reverse-osmosis water |
| Target | Starting water of EC 0.4 to 0.7, which CANNA design their UK feeds for |
| Dose | At the rate on the label, to bring your water up to EC 0.4 to 0.7 |
| Sizes | 1 and 5 litres |
| Brand | Canna |
| Category | CalMag Additives |
How to use
Measure the EC of your tap water before you add any feed. If it is under 0.4, add Calmag Agent to bring it into the 0.4 to 0.7 range CANNA design their UK feeds for, then add your base feed. With RO water it also gives the water some buffer: without that the pH of the feed is very hard to control.
CANNA's Coco and Terra charts assume starting water of EC 0.4, and coco in particular holds on to calcium and magnesium. See the Canna Coco feed chart. You will need an EC meter to measure your water.
Questions
How do I know if I need Calmag Agent?
Measure the EC of your tap water. If it is below 0.4 you are in a soft water area, and Calmag Agent will bring it up to what CANNA consider ideal. If you use RO water you need it too.
Why can't I use RO water on its own with Canna feeds?
RO water has almost no buffer, so the pH of the feed is very hard to control. Calmag Agent brings it back to a level where the standard Canna feeds work.
Growers’ guides
- Canna Coco Feed Chart: A & B, Additives and EC by WeekThe CANNA COCO feed chart week by week: COCO A & B doses, when Rhizotonic, CANNAZYM, CANNABOOST and PK 13/14 go in, and the EC to aim for.
- pH and EC Meters: How to Measure, Calibrate and Look After ThemWhat pH and EC tell you, the targets nutrient makers publish, which meter to choose, and how to calibrate it and look after the probe.
- Coco Coir Guide: Choosing, Feeding and Reusing CocoWhat coco coir is, the coco mixes worth buying, how it compares with clay pebbles and rockwool, and how to feed and reuse it.




