Indoor Hydroponics

Lift the lid of a well-run hydroponic container a month after planting and you’ll find a curtain of roots hanging into dark water, with not a crumb of soil in sight. Up in the light, a lettuce is growing quickly, evenly and spotlessly. It has made no noise, used no electricity of its own and asked for nothing for weeks. That is the quiet charm of hydroponics, and this book shows you how to make it work at home.

Hydroponics has picked up a reputation for gadgetry, jargon and expensive bottles, but you need very little of that. The three systems at the heart of the book can be built from food-safe containers, a few net pots and a bag of growing medium, and two of them have no moving parts at all. Around those builds sits everything they depend on: what roots need, what comes out of your tap, how nutrients work, and the two measurements that run the whole business, EC and pH.

What you’ll build and grow

• A Kratky container, filled once, that can take a lettuce from planting to harvest with no pump
• A deep water culture system with an air pump, for plants that stay in place for months
• A simple wick system, plus the self-watering containers and countertop cups related to it
• Choosing food-safe containers, net pots and growing media, and raising seedlings in plugs
• Testing your tap water, mixing a nutrient solution, and measuring and adjusting EC and pH
• Lights, spacing and fitting a system onto a shelf, with running-cost arithmetic
• A week-by-week routine, including what drifting EC readings are telling you
• Lettuce and other leafy greens, culinary herbs, and day-neutral strawberries with hand pollination
• Root rot, algae, pests and nutrient disorders, with a clear order for diagnosis
• Hygiene between crops and harvest food safety, plus a troubleshooting table and targets at a glance

Whether you’re new or not

If you have never grown anything in water, read in order: every term is explained as it appears, and you don’t need a meter to make a start. A Kratky container of loose-leaf lettuce is suggested as the gentlest first project. If you have grown hydroponically before, you’ll find figures for each crop, the points where expert advice on solution changes, pH targets and oxygen levels differs, and an explanation of why. A few comfortable habits are gently questioned, topping up a Kratky container to the brim among them.

Indoors under lights, most of the method works the same in any month or hemisphere. Where seasons matter, timings are given for the UK and similar temperate climates, with notes for warmer places and the Southern Hemisphere. Measurements are metric first, with imperial in brackets.

Safety as part of the method

Hydroponics brings water near electrics, containers of water within reach of small children, and concentrated nutrients and pH adjusters that can burn skin and eyes. The safety chapter comes before any building, on purpose, and food hygiene is treated the same way, because a system is in effect a kitchen appliance with plants growing out of it.

Peer under the lid now and then: the roots are where it all happens.