Canna Cal-Mag Agent – Calcium & Magnesium for RO Water

Correct calcium and magnesium shortfalls on soft and RO water

Canna Cal-Mag Agent is a concentrated calcium and magnesium supplement for growers running soft or reverse-osmosis water, where these minerals are naturally missing and the feed's E.C. sits too low. It holds an ideal 3:1 calcium-to-magnesium ratio and is also useful late in flower, when demand climbs and older leaves begin to yellow out.

Key Benefits

• 3:1 Ca:Mg ratio matched to what plants actually take up
• Raises E.C. of soft or RO water to a workable base before nutrients go in
• Highly concentrated, so small doses shift the reservoir
• Improves nutrient uptake by clearing the calcium and magnesium bottleneck
• Prevents deficiencies such as interveinal yellowing and late-flower fade
• Builds stronger plants with firmer stems and better leaf structure

Pale, yellowing leaves and weak feed on low-mineral water

RO and soft mains water strip out calcium and magnesium along with everything else, so the tank never reaches target strength and plants show interveinal yellowing and weak stems. Those minerals have to be added back deliberately rather than assumed to already be in the water.

How to Use

• Soft/RO water: add 0.1-0.5ml per litre until you reach an E.C. of about 0.4 mS/cm, then add your base nutrients
• Order of mixing: add Cal-Mag to the water first, mix, then feed and finally adjust pH
• Late-flower fade: dose within the same range to top up calcium and magnesium as demand peaks
• Tip: let the solution stabilise before final pH adjustment, as dissolving minerals can nudge pH