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Hydroponics Nutrients

Hydroponic growing gives you precise control over every nutrient your plants receive — but that precision only works if you start with the right fertilizers. Greenway Biotech's hydroponic nutrient lineup covers everything you need: crop-specific base fertilizers formulated for your exact plant, calcium and magnesium supplements to prevent deficiencies, chelated micronutrients that stay available across a wide pH range, and bloom boosters to maximize fruit quality and yield.

All products in this collection are 100% water-soluble, leave no residue, and are safe for drip systems, NFT channels, DWC, Dutch buckets, Kratky, and recirculating setups.

Shop by Crop

Crop	Best Base Fertilizer	NPK	Why This Formula
Lettuce / leafy greens	Lettuce Fertilizer	8-15-36	Higher N for leaf growth, prevents tip burn
Tomatoes / nightshades	Tomato Fertilizer	4-18-38	High P for fruit set, high K for quality
Cucumbers / melons	Cucumber Fertilizer	8-16-36	Balanced vine crop ratio
Strawberries / berries	Strawberry Fertilizer	8-12-32	Ultra-high K for sweetness and Brix
Peppers / herbs	Pepper & Herb Fertilizer	11-11-40	Very high K for capsaicin and essential oils
General / vegetative	Grow Green 4-2-6	4-2-6	Balanced vegetative growth, any crop

Essential Supplements for Every Hydroponic System

Crop-specific fertilizers cover your NPK and micronutrients, but every hydroponic system also needs calcium and magnesium. Without them, you'll see blossom end rot in tomatoes and peppers, tip burn in lettuce, and interveinal chlorosis across all crops — no matter how well you've dialed in your base formula.

Calcium Nitrate 15.5-0-0 — the standard calcium and nitrogen source for hydroponic reservoirs. Prevents blossom end rot and tip burn. Add to the reservoir first, before any phosphate sources — calcium and phosphate precipitate if mixed directly.

Cal-Mag Plus 2-0-0 — a pre-balanced calcium, magnesium, and iron concentrate. Ideal for coco coir, RO water, and LED-lit grows where Cal-Mag demand is higher than average.

Epsom Salt (Magnesium Sulfate) — adds magnesium for chlorophyll production and sulfur for protein synthesis. Use when magnesium deficiency appears (yellowing between leaf veins on older leaves) or as a preventive supplement at 1 tsp per gallon.

Bloom Phase & Finishing Nutrients

Once plants enter flowering and fruiting, their nutrient priorities shift — less nitrogen, more phosphorus and potassium. Switching to a bloom-phase program at the right time improves fruit size, Brix, color, and firmness.

MKP 0-52-34 — nitrogen-free, water-soluble phosphorus and potassium. The standard bloom booster for hydroponic fruiting programs. Also suppresses powdery mildew when used as a foliar spray. Do not mix in the same tank as calcium nitrate.

Blossom Green 2-6-8 — a low-nitrogen bloom formula that transitions plants from vegetative to reproductive growth. Use when first flowers appear.

Chelated Micronutrients for Hydroponics

Micronutrients lock up at pH extremes — especially iron, which becomes unavailable above pH 6.5. Chelated forms stay dissolved and plant-available across a wider pH range than non-chelated sulfate forms, making them essential for hydroponic systems where pH management is ongoing.

Chelated Iron EDTA 13% — for systems with pH consistently below 6.5. Fast correction of interveinal chlorosis. Chelated Iron DTPA 11% — stays available at slightly higher pH (up to ~7.0), better for systems that run on the higher end. Also available: Chelated Zinc, Chelated Manganese, and Chelated Copper for targeted micronutrient correction.

Frequently Asked Questions

What fertilizers do I need to start a hydroponic system?

At minimum you need a crop-specific base fertilizer (Lettuce 8-15-36, Tomato 4-18-38, etc.) plus a calcium supplement (Calcium Nitrate 15.5-0-0 or Cal-Mag Plus). Most crops also benefit from Epsom Salt for magnesium. Our 4-Part Hydroponic Bundle covers all the bases in one order.

What pH should I maintain in my hydroponic reservoir?

Most hydroponic crops grow best at pH 5.8–6.2. Below 5.5, phosphorus and calcium availability drops. Above 6.5, iron locks up and interveinal chlorosis appears quickly. Check pH daily during the first few weeks of a new system and adjust as needed.

Can I mix all my nutrients together in one tank?

Most nutrients are compatible, but calcium and phosphate must never be mixed directly — they form calcium phosphate precipitate that clogs lines and locks up both nutrients. Always add Calcium Nitrate to the reservoir first, then add phosphate sources (MAP, MKP) from the other side with the pump running. Everything else can generally be added together.

What EC (electrical conductivity) should I target?

EC targets vary by crop and growth stage. Seedlings and leafy greens: 0.8–1.6 mS/cm. Fruiting crops (tomatoes, peppers, cucumbers) in vegetative stage: 1.5–2.5 mS/cm, rising to 2.5–3.5 mS/cm during fruiting. High EC late in fruiting improves Brix and flavor concentration. Start low and raise gradually.

Why are my leaves yellowing between the veins?

Interveinal chlorosis (yellowing between veins while veins stay green) on new growth almost always indicates iron deficiency — but the most common cause is pH above 6.5 locking up iron that's already in solution. Check pH first. If pH is in range, add Chelated Iron EDTA (or DTPA if your pH runs higher). If yellowing starts on older leaves first, suspect magnesium or nitrogen deficiency instead.

How do I keep my hydroponic system healthy?

Hydroponic nutrient management goes hand-in-hand with system health. Learn how to identify and treat root rot in hydroponic plants — one of the most common challenges in recirculating systems.

Further reading: How to Grow Hydroponic Tomatoes · Best Fertilizers for Hydroponics · What Are Hydroponic Strawberries? · How to Treat Root Rot in Hydroponic Plants

Not Sure Which Nutrients to Start With?

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