Hydroponics is a method of growing plants without soil by using mineral nutrient solutions in a water solvent. Some key points: - Hydroponics was first developed in ancient Greece and earliest book on topic was in 1627. German scientists developed first nutrient formula in 1929. - Advantages include being able to grow year-round in smaller spaces, with plants maturing faster. Disadvantages include higher setup costs and need to carefully monitor nutrient solution. - Common hydroponic systems include aquaculture, aggregate, aeroponics, and continuous flow systems which vary in how the roots are supported and nutrient solution is delivered.

1. Hydroponics
Phyllis Putnam
Jean Johnston
Jessica Garner

2. Introduction
-- From Greek - Hydro =
water and pronos =
labor
-- First users of
hydroponics
-- Earliest book, Sylva
Sylarum: Or a Natural
History of Francis
Bacon, 1627

3. -- German scientists
develop the first
nutrient formula,
1929
-- World War II
successful
hydroponic
operation
-- 1970s and 80s and
on to Mars

4. Advantages
Ability to grow vegetables year round
Grow plants in smaller spaces (apt, balcony)
Sterile Medium - No weeds, No soil-borne pests
Healthy Plants - All necessary growth elements readily
available in solution
Plants mature faster (earlier crop)
Smaller root system (smaller spaces again) - Roots don’t
have to spread out to reach food

5. Ability to automate system with a timer - Reduces
time, Gardener can be gone for long periods of
time
Eliminates need for vast farmland
Can raise crops in desert sands - Water is reused,
Less water is used
Lettuce is cleaner (no soil on leaves)
No tillage
Plants often larger and healthier

6. Disadvantages
Cost: Expensive to set up system (fixtures, water pumps,
etc)
Nutrient solution must be kept at original volume - Water
evaporates; add water, Solution can become toxic if too
much nitrates (low light)
Use beneficial predators to control insects
Water quality can be a problem, poor plant growth -
Excessive alkalinity or salt, Softened water, too much
sodium
Roots need oxygen - Need a bubbler or continuous flow
Plants need to be supported (no soil to support)
Cost too high for most commercial growers (grow
expensive crops)

7. Types of Hydroponic Systems
Aquaculture
Aggregate
Aeroponics
Continuous Flow

8. Aquaculture/Aquaponics
Easiest set-up
Roots totally
immersed in nutrient
solution
Must: Support plant
above solution, aerate
solution and prevent
light from reaching
solution
Change solution every
1-2 weeks

9. Continuous Flow System
Typically used in
commercial hydroponics
Nutrient solution
pumped or flowed by
gravity to growing pipes
Bathes the roots then
returns to holding tank
Solution aerates itself as
it flows back
PVC pipe is commonly
used.

10. Aeroponics
Roots of the plant
grow in a closed
container
Misting system of
nutrient solution
Near 100% humidity to
prevent drying
A-Frame containers
are most popular

11. Aggregate Culture
Uses some form of
inert material (i.e.
sand) to support plant
roots
Pump and return
solution using 1 of 2
methods
Flood and drain
method
Trickle feed method