Dyna-Gro Mag-Pro – 1 Qt

Dyna-Gro Mag-Pro (2-15-4) is a concentrated liquid bloom booster formulated with high phosphorus alongside magnesium and sulfur. It is designed to be added to an existing feed schedule during the flowering phase, providing the elevated phosphorus load that fruiting and flowering plants require while correcting common secondary-nutrient deficiencies in one step.

Dyna-Gro Mag-Pro Specifications

The table below summarizes the key product specifications for Dyna-Gro Mag-Pro in the 1 Qt bottle size, derived from the product label and canonical data on file.

Specification	Value
Brand	Dyna-Gro
Product Name	Mag-Pro
NPK Analysis	2-15-4
Primary Nutrients	High phosphorus bloom booster
Secondary Nutrients	Magnesium and sulfur
Container Size	1 Qt (quart / approximately 946 mL)
Formulation	Liquid concentrate
Weight (product + packaging)	3.10 lb
Intended Use	Supplemental additive used in conjunction with a regular feeding program

Why Choose Dyna-Gro Mag-Pro

Mag-Pro addresses two overlapping demands during the bloom phase. Phosphorus drives root energy transfer and flower formation, while magnesium is the central atom in chlorophyll and directly governs how efficiently a plant converts light into carbohydrates. Sulfur supports enzyme activity and protein synthesis. A single product that supplies all three removes the need to source separate calcium-magnesium and bloom-phosphorus supplements, which simplifies dosing and reduces the chance of over-application or formula conflicts.

The 2-15-4 ratio concentrates the phosphorus loading without an excessive nitrogen bump. During late vegetative and flowering stages, growers typically want to reduce nitrogen input and increase phosphorus and potassium. Mag-Pro fits into that shift by providing the P uplift alongside the secondary nutrients that high-intensity flowering can deplete quickly, particularly in recirculating hydroponic systems where sulfur and magnesium are consumed faster than the base nutrient alone replaces them.

Because Mag-Pro is intended to supplement rather than replace a base feed, it integrates into most existing nutrient programs without requiring a complete reformulation of the schedule. Growers using two-part or three-part base nutrient lines can introduce Mag-Pro at bloom onset and adjust the dose according to the plant’s response, which is reflected in leaf color, internodal spacing, and runoff EC.

Best Uses for Dyna-Gro Mag-Pro

Mag-Pro is a supplemental additive intended for the flowering and fruiting phase. The following applications reflect common use cases grounded in the product’s NPK profile and intended use as described on the label.

• Bloom-phase supplementation in hydroponic systems. Recirculating systems (DWC, NFT, ebb-and-flow) deplete secondary nutrients at a faster rate than soil. Mag-Pro replenishes magnesium and sulfur alongside a high-phosphorus dose without requiring a separate Cal-Mag product during flower.
• Correcting mid-bloom magnesium deficiency. Interveinal chlorosis on older leaves during flowering is a common symptom of magnesium deficiency. Adding Mag-Pro to the reservoir or foliar spray schedule can address the deficiency while simultaneously supporting flower development.
• Coco coir and perlite-heavy media. Coco coir is low in cation exchange capacity and does not buffer magnesium or sulfur well. Plants grown in coco benefit from consistent secondary-nutrient supplementation throughout the bloom phase, where Mag-Pro is a direct fit.
• Supplementing single-part or simplified nutrient programs. Growers using a single-part base nutrient often find the phosphorus level insufficient for peak bloom. Mag-Pro adds the phosphorus and secondary-nutrient support without replacing the base program.
• Late-stage push before flush. The high-phosphorus profile makes Mag-Pro suitable for the final weeks of bloom before the flush period, when phosphorus demand peaks and plants begin drawing down stored reserves.

Compatibility

Mag-Pro is formulated as a supplemental additive and is designed to be used alongside an existing base nutrient program rather than as a standalone feed. It is compatible with soil, soilless, and hydroponic growing media. In hydroponic systems, add Mag-Pro to the reservoir after the base nutrients are dissolved and the pH of the solution is stable; mixing order matters for avoiding precipitates.

When using Mag-Pro in combination with other phosphorus-heavy bloom additives, monitor the total phosphorus load in the reservoir or feed solution. In soilless and hydroponic media, excess phosphorus can lock out micronutrients including zinc and iron. Measuring runoff EC and pH at each watering will help detect over-application before visible symptoms appear.

Mag-Pro can be used in conjunction with microbial inoculants and root colonizers. If you are also running a root biostimulant program, products such as Advanced Nutrients Tarantula can be added separately and are generally compatible with mineral bloom additives like Mag-Pro when applied at recommended rates. Similarly, growers using a carbon-based additive such as Earth Juice Hi-Brix Molasses alongside a mineral supplement should mix the carbon source in after confirming EC is within the target range, since both inputs raise the total dissolved solids of the solution.

pH range for nutrient uptake: maintain the feed solution at 5.8–6.2 for hydroponic media and 6.0–6.5 for soil and coco. Outside these ranges, phosphorus and magnesium availability drops sharply regardless of the dose applied.

Dosing Guidelines

Mag-Pro is a concentrated liquid additive. Because no specific dose rate is published in the canonical data available, the following general-use guidelines reflect standard practice for high-phosphorus liquid bloom additives at similar NPK concentrations. Growers should start at the low end and adjust upward based on plant response and runoff EC.

• Starting dose: Begin at approximately 1–2 mL per gallon (0.26–0.53 mL/L) of feed solution during early bloom when introducing Mag-Pro to the schedule.
• Mid-bloom: Doses may be increased to 2–5 mL per gallon (0.53–1.32 mL/L) as phosphorus demand rises and flower sites develop. Monitor EC to avoid over-feeding.
• Mixing order: Add Mag-Pro to the reservoir after the base nutrients have been diluted and the solution pH is close to target. Stir or circulate the reservoir after each addition before measuring final EC.
• Foliar application: A diluted solution (1 mL/L or less) can be used as a foliar spray for fast-acting magnesium correction. Apply during the lights-off period or in low-light conditions to reduce leaf burn risk.
• EC monitoring: After adding Mag-Pro, verify the total EC of the feed solution is within the target range for the growth stage. Reduce the dose of the base nutrient proportionally if EC climbs above the target.

These are general-use guidelines for liquid bloom additives at this NPK range. Always follow label instructions as the authoritative dose reference. Manufacturer documentation and authorized distributor catalogs are the primary references for confirmed dose rates for this product.

Sources & Further Reading