Beginner's Guide to Hydroponics

Carbon Dioxide Plants use carbon dioxide (CO2), light, and water to produce carbohydrates during photosynthesis. Oxygen is released as a by-product. Light plays a crucial role in this process.

Conductivity Nutrient strength in hydroponic solutions is measured using electrical conductivity (EC) or conductivity factor (CF). Pure water does not conduct electricity, but dissolved salts allow electrical current to flow. Home gardeners typically use a CF scale from 0-100, while commercial growers operate within a 2-35 CF range, depending on the plant type.

Germination Germination occurs when a seed starts growing. Factors such as seed viability, temperature, moisture, oxygen, and light influence this process. The first leaves to appear, cotyledons, serve as an initial food source for the plant.

Growing Medium Hydroponics does not use soil. Instead, plants grow in systems that expose roots directly to nutrient solutions or provide support through growing media. Some common hydroponic media include:

• Composted bark: Organic and useful for seed germination.

• Expanded clay pellets: Porous, baked clay for aeration and stability.

• Gravel: Can add minerals; must be clean.

• Oasis foam: Commonly used in floral arrangements.

• Peat moss: Partially decomposed plant matter.

• Perlite: Heated volcanic glass that becomes sponge-like.

• Pumice: Lightweight volcanic material with cavities.

• Rockwool: Melted rock spun into fibers.

• Sand: Usually combined with other media.

• Vermiculite: Similar to perlite but retains nutrients longer.

Hydroponic Systems Hydroponic setups fall into two main categories: media-based systems and water culture systems. They can be either active (using pumps and electronics) or passive (relying on wicking for nutrient distribution).

• Media-Based Systems: Ebb-and-flow, run-to-waste, drip-feed, and bottom-feed.

• Water Culture Systems: Raft, nutrient film technique (NFT), and aeroponics.

Light Light is essential for photosynthesis. Natural sunlight is preferred, but artificial grow lights help compensate for low light conditions. Glass greenhouses maximize light transmission, while indoor growers should optimize placement near windows. Plants need at least 4 hours of darkness for rest.

Macronutrients Plants require 16 essential nutrients. The primary macronutrients include:

• Nitrogen (N): Leaf development.

• Phosphorus (P): Root growth and blooming.

• Potassium (K): Disease resistance and temperature adaptation.

• Sulfur (S): Leaf color enhancement.

• Calcium (Ca): Root and shoot growth.

• Magnesium (Mg): Component of chlorophyll for photosynthesis.

Micronutrients Required in small amounts, micronutrients include boron, copper, cobalt, iron, manganese, molybdenum, and zinc. Hydroponic nutrient solutions contain all essential micronutrients since plants lack soil to draw them from.

Nutrient Solution Hydroponic plants rely on nutrient solutions rather than soil. Distilled water is ideal for preparing nutrient mixes. Store solutions in a cool, dark place to prevent algae growth. When disposing of used nutrient solutions, avoid contaminating nearby water sources.

Osmosis Osmosis enables water and nutrients to pass through root walls. If nutrient concentrations outside the roots are too high, reverse osmosis may occur, pulling moisture out and harming plants. Understanding osmosis helps optimize nutrient absorption without over-fertilization.

Oxygen During the day, plants release oxygen as a by-product of photosynthesis. At night, they absorb oxygen and consume stored energy.

Pests and Diseases While hydroponic gardening avoids many soil-borne pests, problems can still arise. Common threats include fungal infections (Botrytis, Cladosporium, Fusarium, and Verticillium) and pests such as aphids, caterpillars, fungus gnats, nematodes, spider mites, and whiteflies.

Prevention Tips:

• Maintain a sanitary growing environment.

• Use disease- and pest-resistant plant varieties.

• Ensure proper ventilation and temperature control.

• Monitor plants regularly for early signs of issues.