Plagron Hydro A&B — High-Concentration Two-Part Hydroponic Base Nutrients
Best for: Growers running hydroponic systems who want economy, simplicity, and professional results without the premium markup
Our thoughts
This is proper Dutch-engineered nutrient work. One A&B ratio that handles both growth and flowering, no switching bottles halfway through, and at 1:400 concentration it's genuinely economical to run. We rate it highly for first-time hydro growers and experienced growers alike. Clean formula, no tank crystallisation, does exactly what it should.
Plagron Hydro A&B is a two-part mineral base nutrient system designed for hydroponic and inert-medium growing. Built on Dutch engineering, it's formulated to work across all hydro methods — DWC, NFT, flood and drain, run-to-waste — with a single A&B ratio that carries you from vegetative growth through to flowering. The trick is the concentration: at 1:400 mixing ratio, you're getting significantly more nutrient water per litre than competitor products. That means lower cost per dose without compromising formula quality.
How it compares
Plagron Hydro A&B sits in the smart-value territory of professional hydroponic nutrients.
- More concentrated than CANNA Aqua or HESI Hydro — lower per-dose cost
- Unified A&B system throughout the cycle — no switching products like HESI requires
- Built-in calcium and magnesium technology means fewer additional supplements needed compared to General Hydroponics or Advanced Nutrients
- Clean formula with no crystallisation in the tank — less system maintenance headache
- Two-part simplicity compared to three-part competitors, reducing user error
In plain language: you get professional-grade nutrition at a price that makes hydro growing accessible, without cutting corners on performance.
Usage guidance
Plagron Hydro A&B works across different hydroponic setups:
Dosing
Add a maximum of 2.5ml of Hydro A per litre of water (that's your 1:400 ratio). Always use the same quantity of Hydro B with every dose of A. Both parts go in together — you're not balancing them separately.
Deep Water Culture and NFT systems
Ideal for constant-feed or recirculating setups. The clean formula won't clog lines or cause tank buildup.
Flood and drain, run-to-waste
Works equally well. For best economy, run-to-waste minimises tank monitoring and pH drift.
pH and EC management
Target pH between 5.5 and 6.5. The nutrient solution will adjust both pH and EC values as you mix, so monitor regularly — pH will drift slowly upward over time in a stored solution (tank life is roughly four days once mixed). You'll need separate pH up and down solutions.
Growth to flowering transition
Unlike some competitor systems, you don't switch products. The same A&B ratio works for both phases. If you want to push flowering results further, Plagron makes optional additives like Green Sensation, but the base system is complete on its own.
Technical specifications
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Format: Two-part liquid concentrate (A and B bottles)
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Available sizes: 1 litre, 5 litre, 10 litre, 20 litre
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Mixing ratio: 2.5ml per litre of water (1:400 concentration)
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Hydro A NPK: 3-0-1 with 4.2% Calcium (Ca), 0.4% Magnesium (MgO)
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Hydro B NPK: 1-3-6 with 1.4% Magnesium (MgO)
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Trace elements: All included in chelated form for rapid plant uptake
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Target pH: 5.5 to 6.5
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Tank stability: Four days after mixing (monitor pH as it will slowly increase)
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Suitable for: All inert substrates and hydroponic systems (DWC, NFT, flood and drain, run-to-waste, drip irrigation)
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Formula type: Mineral base, no crystallisation in tank
Who this is for
- First-time hydroponic growers who want a straightforward, single A&B system without complexity
- Budget-conscious growers running multiple tanks or large systems where nutrient costs add up fast
- Experienced hydro operators looking to cut product costs without switching from professional-grade performance
- Anyone running DWC, NFT, flood and drain, or run-to-waste systems where reliability and economy both matter
- Growers who want built-in calcium and magnesium support without buying separate Cal-Mag additives
Particularly strong fit for setups where simplicity, consistency, and cost-efficiency are the priority.
Our take
Plagron Hydro A&B is one of the cleanest, most economical entry points into proper hydroponic nutrition. It does what professional base nutrients should do — deliver balanced mineral nutrition, work reliably across different systems, and not rinse your budget in the process. The concentration ratio is genuinely better than what you'll find in most competitor bottles, and the unified A&B approach removes the guesswork from growth-to-flowering transitions.
If you're building a hydro system or replacing your nutrient base, worth picking up while clearance stock lasts. Does exactly what it should, day in, day out.
