Plagron Hydro A & B — Two-Part Hydroponic Base Nutrient for Veg to Harvest
Best for: Growers running hydroponic systems who want a single, straightforward nutrient formula that covers both growth and flowering phases
Our thoughts
This is proper Dutch hydroponic engineering done simply. One formula from veg through to harvest, highly concentrated so your money goes further, and it works clean in any hydroponic system without faffing about with separate growth and bloom products. It's the kind of nutrient that professionals use because it just works.
Plagron Hydro A & B is a two-part concentrated mineral base nutrient designed specifically for hydroponic growing systems. Unlike competitors that require separate products for growth and flowering, this formula does both phases in one hit. It's rich in NPK, calcium, and magnesium, engineered with chelated micronutrients for maximum plant uptake, and formulated to stay stable in your tank without crystallising or locking out. Whether you're running DWC, NFT, flood-and-drain, or drip systems, this won't clog lines and won't leave your reservoir compromised.
How it compares
Plagron Hydro A & B sits in the professional mid-tier of two-part hydroponic systems.
- Single formula for both veg and bloom (CANNA requires separate Vega and Flores products)
- Higher concentration than most competitors — 1:400 mixing ratio means better value per litre
- Simpler than three-part systems (Advanced Nutrients) but more control than one-part feeds
- Chelated micronutrients ensure efficient nutrient uptake in inert substrates
- Clean, stable formula — no organic matter, no crystallisation risk
You're getting Dutch-engineered reliability at a price that makes sense for regular growers and commercial setups alike.
Usage guidance
Plagron Hydro A & B is straightforward once you understand the ratio — equal parts A and B, every single time.
Mixing and dosage
Add 2.5 ml of Hydro A per litre of water, then add exactly the same amount of Hydro B. Use this solution for every watering throughout the entire growing cycle. For imperial: roughly 8–16 ml of each product per gallon, depending on your target EC and plant stage.
Water quality and pH
Target a pH range of 5.5–6.5 (adjust with pH Plus or pH Min). Check your tank pH daily for the first week — it can drift slowly upwards, so monitor it. Keep your tank clean before mixing, and if you're running a recirculating system, ensure you have circulation to keep everything even.
Tank life
Once mixed, the solution is good for up to four days. Don't add organic products (enzymes, boosters, etc.) as they'll spoil within 48 hours and foul your tank. Simple works better here.
Substrate compatibility
Works in all inert mediums — rockwool, hydroton, perlite, coco, grow stones. Suitable for both drain-to-waste and recirculating systems.
Technical specifications
- Format: Two-part liquid concentrate (A and B)
- NPK Hydro A: 3-0-1
- NPK Hydro B: 1-3-6
- Calcium (Hydro A): 4.2%
- Magnesium oxide (Hydro A): 0.4%
- Magnesium oxide (Hydro B): 1.4%
- Micronutrients: Chelated form (full range included)
- Mixing ratio: 1:400 (highly concentrated)
- Recommended pH: 5.5–6.5
- Tank life (mixed): Up to 4 days
- Suitable for: All hydroponic systems (DWC, NFT, flood-and-drain, drip irrigation)
Who this is for
- Intermediate to advanced hydroponic growers wanting to simplify their nutrient schedule
- Anyone running DWC, NFT, or recirculating systems who needs a clean, stable formula
- Commercial operations or large-scale growers where nutrient concentration and cost-per-litre matters
- Growers tired of managing separate growth and bloom products (CANNA style)
- Anyone new to hydroponics but confident enough to mix two parts accurately
Not really suited to beginners with no hydroponic experience — this assumes you understand EC, pH, and basic tank management. But if you've run a hydro system before, you'll find this straightforward and reliable.
Our take
This is a properly engineered two-part nutrient that does what it says without drama. One formula, veg through harvest, stays clean in your tank, and concentrates well enough that your money genuinely goes further than weaker systems. Dutch brands know hydroponics inside out, and this proves it.
If you're setting up a hydroponic system or replacing a nutrient you're not happy with, worth picking up. Does exactly what it should, day in, day out. Good time to buy while clearance stock lasts.
