Cal-Mag Plus 1-Gallon Plant Supplement - Fortified Calcium Mix

Our review of Botanicare Cal-Mag Plus 1-Gallon finds it best suited for growers who need a reliable, concentrated remedy for common calcium and magnesium deficiencies. The bottom line: this is a straightforward, highly fortified add-on you mix with regular waterings or apply as a foliar spray to prevent yellowing, blossom end rot, and weak tissue in container, coco, and soil grows. It is not a complete fertilizer replacement but an effective corrective supplement for plants showing deficiency signs or when using reverse osmosis water.

Key Features

• Highly fortified calcium and magnesium: Provides concentrated levels of Ca and Mg to correct and prevent common nutrient deficiencies in many plant types.
• Includes iron for green growth: Adds iron to support chlorophyll formation and reduce interveinal yellowing on newer leaves.
• Flexible application: Mix with every watering or use as a foliar spray when faster, targeted correction is needed.
• Works with multiple media: Formulated for use in containers, coco coir, hydrogardens, and soil, so it fits a range of growing systems.
• Compatible with nutrient programs: Intended to supplement existing feeding schedules rather than replace base NPK nutrients.
• 2-0-0 NPK formulation: Adds a small amount of nitrogen without upsetting most balanced fertilizer regimens.

Who It's For

Growers using reverse osmosis or very clean water, commercial hobbyists, and container gardeners who frequently see calcium- or magnesium-related symptoms will benefit most from this supplement. Those who use coco coir or hydroponic systems where calcium draw is common will appreciate the concentrated formula for corrective treatments and routine prevention.

It is not aimed at someone looking for an all-in-one primary fertilizer; if a grower needs full NPK feeding rather than a targeted corrective, they should pair this with a complete nutrient line or choose a different product designed as a base feed.

Pros & Cons

Pros

• Strong corrective action on calcium and magnesium deficiencies when used as directed.
• Versatile application options: in waterings or as a foliar spray for faster uptake.
• Works across soil, coco, and hydro setups so it fits many growers' routines.

Cons

• Not a full replacement for base nutrients, so users must maintain a separate fertilizer program.
• Concentrated formula requires careful mixing to avoid over-application.

Specifications

Brand	Botanicare
Primary nutrients	Calcium, Magnesium, Iron
NPK	2-0-0
Volume	1-Gallon
Application	Mix with waterings or foliar spray
Suitable media	Containers, coco, hydrogardens, soil

Our Verdict

Botanicare Cal-Mag Plus 1-Gallon is a dependable corrective supplement for growers battling calcium and magnesium shortages or using purified water. It adds targeted nutrients without replacing base feeds, making it good value for those who need a focused solution to prevent leaf yellowing and structural issues in a variety of growing media.

Frequently Asked Questions

Can this be used with every watering?
Yes, the product is designed to be mixed well and used with every watering as needed to maintain calcium and magnesium levels.

Is it safe as a foliar spray?
Yes, it can be applied as a foliar spray for enhanced growth and faster correction, following label mixing directions.

Will this replace my regular fertilizer?
No, it is a supplemental formula meant to complement an existing nutrient program rather than replace a complete fertilizer.