Humboldt Nutrients Master A – 5 gal

Humboldt Nutrients Master A is Part A of the two-part Master A&B mineral fertilizer system, formulated for all plant types and growth stages. What distinguishes this series from conventional two- and three-part programs is the use of natural amino acid chelation for all heavy metal micronutrients — a method that is 100% biodegradable and avoids the synthetic EDTA and EHDDA chelating agents common in competing products. This 5-gallon jug (approximately 50 lb) is suited to commercial and high-volume hobbyist grows where per-gallon nutrient costs matter.

Humboldt Nutrients Master A – 5 gal Specifications

The following table covers the key physical and formulation attributes of Humboldt Nutrients Master A in the 5-gallon size, drawn from the canonical product data.

Specification	Value
Brand	Humboldt Nutrients
Product Name	Master A – Part A of Master A&B Two-Part System
Container Size	5 gallon (approx. 18.9 L)
Weight	~50 lb (50.0008 lb)
Micronutrient Chelation	Natural amino acid chelation (not EDTA or EHDDA)
Biodegradability	100% biodegradable
System Type	Two-part mineral base nutrient (Part A)
Suitable For	All plant types, all growth stages

Why Choose Humboldt Nutrients Master A

Most commercial two-part and three-part base nutrient programs deliver micronutrients using EDTA (ethylenediaminetetraacetic acid) or EHDDA chelating agents. These are synthetic industrial chemicals that persist in soil and waterways after application. Humboldt Nutrients built the Master A&B series specifically to address this. Here is what sets it apart:

• Amino acid chelation of all micronutrients. Natural amino acids replace synthetic EDTA and EHDDA as the chelating agents for heavy metal micronutrients (iron, manganese, zinc, copper, etc.). Amino chelates are recognized and transported by plant cells in the same pathways as organic-matter-derived chelates, which can improve uptake efficiency in a range of media.
• 100% biodegradable formula. Because no synthetic industrial chelants are used, the entire formulation breaks down in soil and wastewater streams without leaving persistent residues. This is particularly relevant for growers operating near waterways or in jurisdictions with nutrient runoff regulations.
• Designed for all plant types. The Master A&B ratio is formulated as a universal base, meaning it works across vegetables, flowers, herbs, and fruiting crops in both soil and hydroponic media.
• Made with high-quality mineral ingredients. Humboldt Nutrients sources mineral inputs for this series at a quality tier above the commodity-grade imports commonly used in budget two-part programs.
• 5-gallon bulk volume. At roughly 50 lb per jug, this size suits commercial production, large hobby grows, and operations that need to reduce per-gallon input cost and resupply frequency.

For growers who have run synthetic chelant-based programs and are concerned about soil biology or effluent quality, the Master A&B system provides a functionally equivalent base program with a meaningfully different input chemistry.

Best Uses for Humboldt Nutrients Master A

Because Master A is the first half of a two-part base nutrient system, its best applications are situations where a grower needs a complete, scalable mineral foundation rather than a specialty additive.

• Commercial hydroponic production. Recirculating systems — NFT, DWC, and flood-and-drain — benefit from a clean two-part formulation that mixes predictably and does not introduce synthetic chelant residues into the reservoir. The 5-gallon size reduces the number of handling events needed during a production cycle.
• Coco coir and perlite media. Amino chelation is well-suited to coco-based media, where pH can shift quickly. Amino acid chelates remain available across a wider pH band than EDTA chelates, which can precipitate out at pH values common in coco.
• Soil and organic-amended grows. Growers mixing synthetic base nutrients into a living-soil approach will appreciate that the amino chelation does not disrupt microbial populations the way persistent synthetic chelants can. It integrates with beneficial inoculants such as mycorrhizae and bacterial root colonizers, making it a natural pairing with products like Advanced Nutrients Tarantula or other root microbial supplements.
• High-volume hobbyist and co-op purchasing. At 5 gallons, this jug covers a full season for a serious hobby grow or can be split across multiple growers purchasing cooperatively. The unit cost per gallon of nutrient solution drops meaningfully at this size relative to 1-gallon and 2.5-gallon options.
• Operations with effluent compliance requirements. Facilities that must manage nutrient runoff — greenhouses discharging to municipal sewer or near surface water — benefit from a base that is certified fully biodegradable, reducing the monitoring burden for synthetic chelant compounds.

Humboldt Nutrients Master A vs Conventional Two-Part Programs

The two-part base nutrient category is crowded. Most programs — from budget imports to well-known hydroponic brands — share a common formulation strategy: synthetic EDTA or EHDDA chelants keep micronutrients soluble in concentrate. This works, and plants grown on these programs perform well in most controlled environments. The trade-off is the environmental footprint of those chelants once they leave the reservoir via drain-to-waste or runoff.

Humboldt Nutrients Master A&B occupies a different position in that spectrum. By replacing synthetic chelants with natural amino acids, it achieves comparable micronutrient availability — the published rationale is that amino acid chelates engage plant uptake mechanisms that evolved around organically chelated minerals — while producing a formula that fully breaks down post-application. For growers whose primary concern is plant performance in a closed environment with no effluent going to waterways, the difference may be marginal in practice. For growers who manage soil biology, discharge compliance, or sustainable certification requirements, it is a substantive distinction.

Compared to three-part programs, the Master A&B two-part structure also reduces formulation complexity: you are balancing two bottles rather than three, which simplifies mixing, reduces the number of potential interaction errors, and lowers the stocking overhead in a commercial facility. Growers who want to layer in additional function — root colonizers, carbohydrates, or molasses-based sugars — can do so by adding targeted supplements like Earth Juice Hi-Brix Molasses without disrupting the base nutrient balance.

Compatibility

Humboldt Nutrients Master A is formulated as a universal mineral base and is compatible with the full range of hydroponic and soil growing systems. The following notes are derived from the product’s design parameters as stated by the manufacturer.

• Growing media: Compatible with rockwool, coco coir, perlite, expanded clay (hydroton), and standard potting soils. The amino chelation chemistry is particularly well-suited to coco, where micronutrient lock-out at shifting pH values is a common issue.
• Hydroponic systems: Suitable for use in recirculating deep water culture (DWC), nutrient film technique (NFT), ebb and flow (flood and drain), drip systems, and aeroponics. No incompatibility with standard recirculating system materials (PVC, polyethylene, EPDM).
• Companion nutrients and additives: As a two-part base, Master A is designed to be used alongside Master B. Additional supplements and additives — root inoculants, silica products, bloom boosters — can typically be added to the reservoir after mixing Part A and Part B, following standard nutrient addition order (adjust pH last). A product like PureCrop1 can be incorporated into an IPM rotation without conflicting with the Master A&B base nutrient program.
• pH range: Standard hydroponic operating range of 5.5–6.5 for hydroponics, 6.0–7.0 for soil. Amino chelates maintain availability across this band more consistently than EDTA chelates, which begin to lose solubility at the upper end of the hydroponic range.
• Water source: Compatible with RO water, well water, and municipal water supplies. Hard water (high calcium/magnesium) does not interfere with the amino chelation chemistry in the way it can react with some synthetic chelants.

Dosing Guidelines

The canonical product data does not include a published per-gallon dose rate for this specific size; the following represents standard practice for a two-part mineral base nutrient program of this type. Growers should consult the Humboldt Nutrients feed chart available on the manufacturer’s website for confirmed dose rates by growth stage.

• General approach: Add Master A to the reservoir or mixing tank first. Mix thoroughly before adding Master B. Never combine concentrates directly — always dilute each part into water separately before introducing the second part.
• Mixing order: Start with plain water (ideally at the target pH range). Add Master A and mix. Then add Master B and mix. Add any additional supplements after both base parts are fully dissolved. pH-adjust last.
• EC monitoring: Use a calibrated EC or TDS meter to verify the final nutrient solution strength before applying to plants. Target EC ranges vary by growth stage and crop type; seedlings and young vegetative plants typically receive a lower EC than plants in peak flowering.
• Seedlings and propagation: Use a reduced dose or hold off on base nutrients entirely until roots are established, depending on the propagation medium. Many growers start at 25–50% of the recommended dose for the first week after transplant.
• Flushing: Because Master A&B uses amino chelation and is 100% biodegradable, it leaves minimal residue in media. Standard end-of-cycle flushing with plain pH-adjusted water is still recommended to clear accumulated salts before harvest.

For confirmed dose rates and a full feed schedule, refer to the Humboldt Nutrients official website and the Master A&B product page.

Sources & Further Reading