In traditional soil gardening, plants get their essential minerals from the earth. In hydroponics, the water is the soil. A nutrient mix, or nutrient solution, is the precise blend of these essential minerals, dissolved in water, that your plants need to not only survive but thrive. Getting this formula right is the single most critical factor for success in any hydroponic system.
The solution provides everything the plant would naturally get from soil, divided into two main categories: macronutrients (like Nitrogen, Phosphorus, and Potassium) which are needed in large amounts, and micronutrients (like Iron, Boron, and Zinc) which are needed in tiny, trace amounts. Both are absolutely vital. An imbalance or deficiency in any one of these can lead to poor growth, disease, or crop failure.
When looking at commercial fertilizers, you'll often see three numbers, such as 10-10-10 or 4-18-38. This is the N-P-K ratio, representing the percentage of Nitrogen, Phosphorus, and Kalium (Potassium) in the mix. A 'grow' formula for leafy development will be high in Nitrogen, while a 'bloom' or 'fruiting' formula will be higher in Phosphorus and Potassium to support flowering and fruit production. Understanding this ratio helps you choose the right product for your plant's current stage of growth.
This page will guide you through the different ways to source your nutrients—from simple pre-mixed solutions to creating your own from scratch—and provides basic recipes to get you started.
How to Source Your Nutrients
Pros
- Very easy to use
- Minimal measuring and no complex mixing
- Good for small-scale hobbyists
Cons
- Most expensive option per gallon
- Heavy to ship and store
- Less control over individual nutrient ratios
Pros
- Much cheaper than liquid nutrients
- Long shelf life and easy to store
- Allows for some customization of the final mix
Cons
- Requires a digital scale for accurate measuring
- Can be intimidating for beginners
- Takes more time to prepare
Pros
- Lowest possible cost
- Complete control over your nutrient formula
- Enables you to tailor mixes for specific plants and growth stages
Cons
- Requires precision and knowledge of plant nutrition
- Sourcing multiple individual ingredients can be difficult
- High potential for error if not done correctly
Nitrogen (N)
Role: Essential for leaf growth and chlorophyll production. Gives plants their green color.
Deficiency Signs: Yellowing of older, lower leaves; stunted growth.
Phosphorus (P)
Role: Crucial for root development, flowering, and energy transfer.
Deficiency Signs: Stunted growth, and leaves may turn dark green or purplish.
Potassium (K)
Role: Regulates water uptake and is vital for overall plant health and disease resistance.
Deficiency Signs: Yellowing or browning on the edges of older leaves.
Calcium (Ca)
Role: Builds strong cell walls, crucial for new growth at the root and shoot tips.
Deficiency Signs: Stunted or deformed new growth (e.g., blossom-end rot in tomatoes).
Magnesium (Mg)
Role: The central atom of the chlorophyll molecule; essential for photosynthesis.
Deficiency Signs: Yellowing between the veins of older leaves (interveinal chlorosis).
Sulfur (S)
Role: Important for protein formation and gives many plants their flavor and odor.
Deficiency Signs: Yellowing of new, younger leaves; often mistaken for Nitrogen deficiency.
Iron (Fe)
Role: Used in chlorophyll synthesis and enzyme function.
Deficiency Signs: Yellowing between veins of new, young leaves.
Manganese (Mn)
Role: Aids in photosynthesis, respiration, and nitrogen assimilation.
Deficiency Signs: Interveinal yellowing on young leaves, sometimes with dark spots.
Boron (B)
Role: Essential for cell wall formation and reproductive growth.
Deficiency Signs: Brittle, dead, or deformed new growth.
Zinc (Zn)
Role: Plays a role in enzyme activation and protein synthesis.
Deficiency Signs: Stunted growth and reduced leaf size.
Copper (Cu)
Role: Activates enzymes and is involved in photosynthesis.
Deficiency Signs: Dark green, stunted new leaves that may wilt.
Molybdenum (Mo)
Role: Needed for nitrogen fixation and converting nitrate to usable forms.
Deficiency Signs: Rare, but resembles nitrogen deficiency with yellowing on older leaves.
DIY Nutrient Mix Recipes (from Raw Salts)
- Calcium Nitrate4g
- Potassium Phosphate1g
- Potassium Sulfate1g
- Magnesium Sulfate2g
- Trace Elements Mix0.25g
Compatible Plants
- Lettuce (Romaine, Butterhead, Iceberg)
- Spinach
- Kale (Lacinato, Curly)
- Swiss Chard
- Arugula
- Bok Choy
- Mustard Greens
- Watercress
- Endive
- Mizuna
- Tatsoi
- Collard Greens
- Calcium Nitrate3g
- Potassium Phosphate1.5g
- Potassium Sulfate1g
- Magnesium Sulfate1.5g
- Trace Elements Mix0.3g
Compatible Plants
- Basil (Genovese, Thai)
- Mint
- Cilantro
- Parsley
- Chives
- Oregano
- Thyme
- Rosemary
- Dill
- Sage
- Tarragon
- Marjoram
- Chervil
- Fennel
- Anise
- Lavender
Requires larger systems like Dutch Bucket or DWC with support structures (trellises).
- Calcium Nitrate5g
- Potassium Phosphate2g
- Potassium Sulfate2g
- Magnesium Sulfate2.5g
- Trace Elements Mix0.4g
Compatible Plants
- Tomatoes (Dwarf, Vining)
- Peppers (Bell, Hot)
- Cucumbers
- Strawberries
- Zucchini
- Eggplant (Japanese)
Disclaimer: These are general purpose mixes. Always research the specific needs of your plants and adjust accordingly. Start with a weaker solution and increase strength as needed. Monitor your plants for signs of nutrient deficiency or toxicity.