Hydroponic Nutrients Complete Guide
Complete guide to hydroponic nutrients. Learn mixing ratios, feeding schedules, and troubleshooting for healthy plants in UK conditions.
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Take Our QuizPlants need food. In hydroponics, you're the chef. Understanding nutrients transforms you from someone following a recipe to someone who can diagnose and solve problems.
The Basics: NPK:
Nitrogen (N): Drives leafy growth. Deficiency shows as yellowing older leaves.
Phosphorus (P): Supports roots and flowering. Deficiency shows as purple tinting.
Potassium (K): Overall plant health and disease resistance. Deficiency shows as brown leaf edges.
These are the macronutrients. Plants need them in relatively large amounts.
Secondary and Micro Nutrients: Calcium, magnesium, sulphur, iron, manganese, zinc, and others. Quality hydroponic nutrients include these. Deficiencies are rarer but possible.
EC and TDS: Electrical Conductivity (EC) or Total Dissolved Solids (TDS) measure nutrient concentration. Higher numbers mean stronger solution.
Typical ranges: Seedlings: EC 0.5-1.0 Leafy greens: EC 1.0-1.5 Fruiting plants: EC 1.5-2.5
You don't strictly need a meter to start. Following bottle instructions at half strength works for beginners. A meter (around £15-30) helps with precision as you advance.
Feeding Schedules:
Seedling stage: Half strength nutrients. Roots are delicate.
Vegetative growth: Full strength nitrogen-focused feeding. This is when plants bulk up.
Flowering/fruiting: Shift to phosphorus and potassium. Nitrogen drops.
Changing Your Reservoir: Nutrients deplete unevenly. Plants take what they need, leaving imbalances. Fresh solution every 1-2 weeks prevents problems.
In between changes, top up with plain water (not more nutrients). Concentration increases as plants drink water but leave nutrients behind.
Overfeeding Signs:
Nutrient burn: Brown, crispy leaf tips Dark green leaves: Nitrogen excess Slow growth: Overall toxicity
If in doubt, dilute. Plants recover from underfeeding faster than overfeeding.
Our Recommendation: Start simple. One brand, one schedule, following instructions. Don't mix brands or add supplements until you understand the baseline.
Keep notes. What worked, what didn't. Your specific water and conditions will teach you more than any guide.
Products Mentioned in This Guide
General Hydroponics Flora Series
General Hydroponics
Industry standard three-part nutrient system. FloraGro, FloraBloom, FloraMicro. Decades of proven results across every c...
View on AmazonCANNA Aqua Vega & Flores
CANNA
Dutch quality two-part system designed for recirculating hydroponic systems (DWC, NFT). Clean formulation that doesn't c...
View on AmazonEC/TDS Meter
Generic
Digital EC and TDS meter for measuring nutrient strength. Essential for preventing overfeeding and underfeeding. Measure...
View on AmazonCal-Mag Supplement
Generic
Calcium and magnesium supplement essential for soft water areas and preventing deficiencies. Prevents blossom end rot in...
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Start the QuizFrequently Asked Questions
How often do I add nutrients to hydroponics?
Kratky method: once at setup. DWC/NFT: top up weekly, full change every 2-3 weeks. Monitor EC/TDS - when it drops 30%, top up. When it rises (plants drinking more water than nutrients), change solution.
Can you overfeed hydroponic plants?
Yes, and it's common with beginners. Signs: burnt leaf tips, stunted growth, salt buildup on containers. Start at 50-75% recommended strength, increase gradually. Leafy greens need less than fruiting plants.
What is EC and TDS in hydroponics?
EC (Electrical Conductivity) and TDS (Total Dissolved Solids) measure nutrient concentration. Lettuce: 0.8-1.2 EC (400-600 ppm). Tomatoes: 2.0-3.0 EC (1000-1500 ppm). A £15 EC meter saves guesswork and prevents problems.
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