What is Hydroponics? Soilless Food Cultivation

Commercial and school growers use three primary system designs:

1. Deep Water Culture (DWC): Plant roots suspend continuously in an aerated reservoir of bubbly nutrient water.

2. Nutrient Film Technique (NFT): A thin, continuous stream of water flows down sloping gullies over root tips.

3. Ebb and Flow (Flood & Drain): A grow tray flooded periodically with water that drains back into the sump.

Students build a self-contained hydroponic planter using recycled plastic bottles:

Step 1: Cut a clear 2-liter soda bottle horizontally 4 inches below the bottle cap.

Step 2: Invert the top neck into the bottom reservoir like a funnel.

Step 3: Thread a 10-inch strip of cotton or microfiber cloth through the bottle mouth down into the reservoir as a wicking cord.

Step 4: Fill the top funnel with expanded clay pebbles or perlite and plant a lettuce seedling.

Hydroponic farmers must monitor two critical water parameters daily:

pH (Potential of Hydrogen): Must stay between 5.5 and 6.5. If water is too acidic or too alkaline, plants suffer 'nutrient lockout' and cannot absorb iron or phosphorus.

EC (Electrical Conductivity): Measures total dissolved salts/nutrients in parts per million (PPM) to ensure the solution is neither too weak nor burning roots.

In January, Tyonek temperatures drop below zero and daylight shrinks to under 5 hours. Fresh greens flown in from California take days to arrive and spoil quickly.

Classroom and community hydroponic systems run under efficient LED lights, providing crisp, vitamin-rich spinach, kale, and microgreens regardless of blizzards outside!

Students log daily reservoir water levels, leaf counts, and pH readings in their hydroponic laboratory binder.

Teams discuss how expanding indoor agriculture in tribal facilities can reduce grocery store costs and provide living agricultural education.