Botanicare 32oz Cal-Mag Plus (12/CS)

Botanicare Cal-Mag Plus (2-0-0) is a highly fortified calcium, magnesium, and iron plant supplement designed to correct common deficiencies that appear when growing in coco coir or when using reverse osmosis water. Available in a 32 oz bottle sold as a case of 12, it integrates into any nutrient program as a targeted additive and can also be applied as a foliar spray.

Cal-Mag Plus Specifications

Why Choose Cal-Mag Plus

Cal-Mag Plus addresses one of the most common nutrient management problems in controlled-environment growing: secondary nutrient deficiencies that standard base nutrients do not fully compensate for. Here is what makes it a practical choice:

• Formulated for RO water users. Reverse osmosis filtration strips calcium and magnesium from source water. Cal-Mag Plus replenishes both minerals at concentrations that keep your nutrient solution balanced, regardless of the base water profile.
• Compensates for coco coir’s calcium demand. Coco coir naturally chelates calcium, drawing it away from the root zone. Adding Cal-Mag Plus to your feed schedule prevents the tip burn and interveinal chlorosis that often appear in coco grows within the first few weeks.
• Includes iron alongside calcium and magnesium. Many cal-mag products stop at two minerals. The inclusion of iron in the 2-0-0 formula broadens the deficiency correction without requiring a separate iron supplement.
• Compatible with any nutrient line. Cal-Mag Plus is sold as a supplement, not a base nutrient. It works alongside your current A/B or three-part program without disrupting NPK ratios or requiring a reformulation of your feed chart.
• Dual-application flexibility. The same concentrate can be dosed into the reservoir for root-zone feeding or diluted into a foliar-spray tank to address visible deficiency symptoms between watering cycles.

Best Uses for Cal-Mag Plus

Cal-Mag Plus is a targeted additive, not a base nutrient. It belongs in your program under specific growing conditions where secondary nutrient deficiencies are predictable or already visible.

• Coco coir systems. Run Cal-Mag Plus from the first feed through the full grow cycle. Coco’s natural cation exchange properties make ongoing supplementation necessary rather than optional.
• Reverse osmosis water. RO-fed reservoirs lack the mineral buffering that tap water provides. Dose Cal-Mag Plus before adding base nutrients to establish a stable calcium and magnesium baseline.
• Hydroponic systems with soft source water. Deep water culture, NFT, and ebb-and-flow set-ups drawing from low-mineral municipal or well water benefit from regular Cal-Mag supplementation to prevent slow onset deficiencies.
• Foliar correction of visible symptoms. When interveinal chlorosis, tip burn, or stunted new growth appears, a foliar application of Cal-Mag Plus delivers minerals directly to leaf tissue while root-zone adjustments take effect over the following days.
• High-demand flowering stages. Calcium uptake increases during rapid cell division in early bloom. Adding Cal-Mag Plus during the transition and early-flower phases supports cell wall integrity without pushing nitrogen levels higher than needed.
• Commercial and commercial-scale operations. The 12-bottle case format reduces per-unit cost and minimizes reorder frequency for facilities running multiple reservoirs or mixing large feed volumes weekly. If you are also building out your root inoculant program, Advanced Nutrients Tarantula pairs well with a balanced cal-mag additive in coco and soilless systems.

Sources & Further Reading