Self-Reliance · Food
Water carries the nutrients instead of soil. A windowsill jar of lettuce and a garage full of NFT channels run on the same basic chemistry, just at different scale.
Getting startedThe case
Hydroponics grows plants with their roots directly in a nutrient-rich water solution rather than soil, delivering water, oxygen, and minerals straight to where the roots can use them. There is no compost to build, no weeds to pull, and a windowsill or a garage corner can produce a steady supply of lettuce, herbs, or greens year-round, independent of outdoor growing season.
The honest first-year picture: the plant's entire mineral diet now comes from a bottle instead of the soil buffering mistakes for you. That trade brings speed and control, and it also means a grower has to learn to read a test kit and mix a solution correctly from day one. Leafy greens and herbs are the forgiving starting crop; fruiting plants like tomatoes come later, once the basics are routine.
Getting started
No pump, no electricity, and almost no daily attention. A net pot sits in or above a reservoir and the plant draws solution up as it grows. Herbs and lettuce only, and the standard first attempt[1].
Under $30 for a single-plant setup
Roots hang in an aerated reservoir with plants supported on a floating raft. The large water volume resists rapid swings in temperature, pH, and nutrient strength, which makes it one of the more forgiving active systems[2].
$100 to $300 for a home-scale build
A thin, continuously moving film of solution flows through sloped channels over the roots. Efficient with water and fertilizer, but a clogged channel or a pump failure can stress plants within hours, so it rewards experience more than a first system should[1].
Highest management overhead of the three
Most home growers start with wick or Kratky, move to deep water culture once the basics are routine, and treat NFT as a later upgrade.
Mixing and testing the solution
Every hydroponic solution is built around two numbers: electrical conductivity (EC), which measures total dissolved nutrient concentration, and pH, which determines whether the plant can actually absorb what's dissolved in the water[3]. Most leafy greens and herbs want a pH between roughly 5.5 and 6.5. Outside that range, nutrients can be present in the water and still unavailable to the plant, a condition growers call nutrient lockout.
Mix fertilizer concentrates into water one at a time and let each dissolve before adding the next; combining two concentrated stock solutions directly with each other, rather than into the reservoir, is a common way to form insoluble precipitates that clog pumps and lock up nutrients[3]. Test EC and pH on a fixed schedule, not just when a plant looks unhappy, since both drift as the plants and any microbes in the system use water and nutrients over time.
Change the full reservoir on a regular schedule rather than only topping it off. Continuously topping off lets salts concentrate unevenly and lets whatever is growing in the water, algae, biofilm, or bacteria, build up rather than get flushed out.
The pH bottle is a corrosive chemical, not plant food
Most "pH down" products are concentrated phosphoric, nitric, or sulfuric acid, and most "pH up" products are concentrated potassium hydroxide. Both are strong enough, undiluted, to burn skin and eyes on contact[4]. Workplace safety rules treat any chemical with a pH at or below 2 or at or above 11.5 as corrosive enough to require immediate flushing on contact, a useful line for judging how seriously to take a bottle that looks like ordinary plant food[5].
Wear gloves and eye protection when handling the concentrate, always add adjuster to water rather than water to adjuster, store pH up and pH down in separate labeled containers, and never reuse a scoop or dropper between the two. Keep all concentrates away from children and pets, the same as any household corrosive.
The second risk belongs to the food itself, not the chemicals. Because roots sit directly in circulating water instead of soil, a contaminated reservoir can spread bacteria to every plant in the system at once[6]. Wash hands before harvesting, keep the reservoir covered from direct sun to limit algae growth, and treat a hydroponic system with the same food-safety discipline as any kitchen surface that touches what you eat[7].
What goes wrong
01
Adjusting pH or nutrient strength by eye, based on how a plant looks, catches a problem days after it started. A cheap EC and pH meter pays for itself in the first failed batch it prevents.
02
Treating pH adjuster like dish soap, no gloves, no care about splashes, is how a bottle of plant food becomes a chemical burn. Respect the concentrate every time, not just the first time.
03
Topping off water indefinitely without a full reservoir change lets salts concentrate unevenly and lets algae and bacteria accumulate in exactly the water your food's roots sit in.
Where this fits
Add fish to the loop and the plants' nutrients come from waste instead of a bottle, trading chemical handling for a different set of tradeoffs.
Aquaponics guide →
A soil-based bed is the lower-cost, lower-maintenance comparison point, useful for deciding which approach fits a household first.
First garden guide →
Safe handling once greens leave the system, including the washing and storage rules that apply to any fresh produce.
Food safety guide →
This page sits at Tier 1 of the Preservation Hierarchy: fresh food, harvested and eaten within days.
Sources