Cal-Mag Plus 1-Gallon Plant Supplement - Corrects Ca, Mg & Fe

Our review of this 1-gallon Cal-Mag Plus finds it most useful for growers who need a straightforward fix for nutrient shortages. Botanicare formulated this concentrate to supply highly fortified amounts of calcium, magnesium and iron, so the single biggest reason to buy is its targeted correction of common deficiencies without overhauling an existing feeding schedule. The review focuses on ease of use, compatibility with common grow systems, and whether the 2-0-0 NPK blend offers practical benefit beyond trace element correction.

Key Features

• Highly fortified formula: Provides concentrated calcium, magnesium and iron to correct deficiency symptoms quickly and reliably when mixed into the water.
• Flexible application: Can be added to every watering or used as a foliar spray for faster uptake during acute deficiency situations.
• Broad system compatibility: Suitable for containers, coco, hydro gardens and soil, so it fits into most common home and commercial setups.
• Supplemental use: Designed to work alongside an existing nutrient program so growers do not need to replace their base feed to address Ca and Mg shortfalls.
• Low NPK base: The 2-0-0 NPK formulation supplies minimal nitrogen and no phosphorus or potassium, reducing the risk of altering bloom or vegetative balance when used correctly.

Who It's For

Botanicare Cal-Mag Plus is aimed at hobby and small-scale growers who notice leaf curling, interveinal chlorosis, or stunted new growth that point to calcium, magnesium or iron shortages. It is especially useful for those using coco mixes, soilless media or recirculating hydro gardens where nutrient lockout and imbalances are more common.

Growers who prefer an all-in-one base nutrient with balanced NPK might look elsewhere, because this product is a targeted supplement rather than a full feed. Also, those who want organic-certified inputs should verify compatibility, since this is a formulated mineral supplement intended to be mixed and measured into feed water.

Pros & Cons

Pros

• Concentrated dose addresses calcium and magnesium deficiencies effectively when applied properly.
• Works as a foliar spray or soil drench for flexible treatment options.
• Designed to supplement existing nutrient programs without major adjustments.
• Compatible with containers, coco, hydro and soil setups common to home growers.

Cons

• Not a standalone fertilizer; users must continue their regular nutrient schedule.
• Requires careful mixing and dosing to avoid over-application in sensitive setups.

Specifications

Product	Cal-Mag Plus
Size	1-Gallon
NPK	2-0-0
Primary nutrients	Calcium, Magnesium, Iron
Use methods	Add to water or foliar spray
Compatible media	Containers, coco, hydro gardens, soil

Our Verdict

For growers who need a reliable correction for Ca, Mg and Fe shortages, the 1-gallon Cal-Mag Plus is a practical, good-value supplement that integrates with most feeding programs. It is not a full fertilizer replacement, but it delivers targeted nutrients in a flexible format that helps restore plant vigor and avoid recurring deficiency issues.

Frequently Asked Questions

How is Cal-Mag Plus applied?
Mix well and add to every watering as needed, or apply as a foliar spray for quicker correction of deficiency symptoms.

Will this replace my base nutrient?
No. It is a supplemental product intended to correct calcium, magnesium and iron deficiencies while you continue your normal nutrient regimen.

Can it be used in hydroponic systems?
Yes. The formula is suitable for hydro gardens, containers, coco and soil when mixed according to instructions.