What is a “Media Based” hydroponic system?

Lesson #3 Media and Lighting

1. To describe the comparative advantages and disadvantages of hydroponic media. 2. To describe the quantity and quality of light needed for hydroponic plant production. 3. To select lights for hydroponic plant production.

1. What are the char. of a good media? a. Firmly anchors the plant b. Will not break down c. Absorbs and retains moisture d. Porous enough to allow air circulation and drainage e. Protects plant roots from temperature extremes

2. What types of media are used in hydroponics? a. Sand b. Rockwool c. Expanded Clay Pellets d. Perlite e. Vermiculite f. Coconut Fiber

Plentiful, long-lasting, easy to clean and relatively inexpensive. Heavy when wet and dries out quickly. Use course not fine sand

Inorganic, sterile. Made from basalt, rock, limestone, and silica. Comes in block cubes and slabs. Excellent water/air hold capacity. Preferred by “commercial growers”

Porous, retain water/air. Be sure to rinse before using to remove dust

Mined from lava flows, then crushed, screened and heated. Light weight, good water retention, sterile. Rinse before using.

Plentiful, long-lasting, easy to clean and relatively inexpensive. Heavy when wet and dries out quickly.

Porous, good water/air holding capacity, long lasting

3. How much light do plants need in the hydroponic systems in a greenhouse? hours per day

4. What quality of light is needed for plant growth? Flowering plants need stronger red light. Leaf vegetables such as lettuces and most house plants want blue light for better vegetative growth.

5. What type of lights should we use for our indoor hydroponic units? Fluorescent lights Metal Halide Lamps High Pressure Sodium Lamps

Best for germination and plants less than two feet tall. Not generally recommended. Use combination of “warm light.”

(Metalarc- MA, Super Metalarc – SMA) are the best artificial light source available today. Emit correct amounts of blue and red light.

Emit plenty of red light but not enough blue. Very efficient and economical so often used despite short comings.

1. To describe the comparative advantages and disadvantages of hydroponic media. 2. To describe the quantity and quality of light needed for hydroponic plant production. 3. To select lights for hydroponic plant production.

Purpose: To identify the absorption capacity of various types of growing media

Growing Media Lab

Please list 3 characteristics of a quality growing media?