Stop guessing. Start growing fresh greens without a single watt of electricity.

Most beginners fail at passive hydroponics for one simple reason: they use a 1-liter jar that is too small and top up the water—submerging the oxygen roots and drowning the plant.

Zero-Watt Hydroponics turns the published University of Hawaii trials by Dr. Bernard A. Kratky into a clear, step-by-step 38-page manual for complete beginners. Every figure backed by research is clearly labeled, and every practical home estimate is marked so you never have to guess.

Inside the 9 Chapters & 5 Practical Appendices (38 Pages):

1. Chapter 1 – How the Kratky Method Really Works: The 4 core rules, capillary action, and how oxygen roots vs. water roots form automatically.
2. Chapter 2 – The Water-Level Rule (& Why 1L Jars Disappoint): Exact starting fill heights (within 4 cm of the top) and why a single head of lettuce actually needs 3 to 6 liters of solution.
3. Chapter 3 – Containers & Setup on a Small Budget: How to set up 4L bottles, 20L buckets, or storage boxes while preventing algae, warm water, and mosquitoes.
4. Chapter 4 – Net Pots, Substrates & Seeds: Slitted cup DIY options, peat/perlite/coco coir rules, direct seeding vs. transplanting, and heat-tolerant varieties.
5. Chapter 5 – Nutrients Without the Confusion: Target EC levels by crop, the step-by-step mixing order so calcium never locks up into milky water, and tap-water salt math.
6. Chapter 6 – The Big Table: Exact water volume, EC target, and harvest timeline for lettuce, herbs, cucumbers (100–130 L), and tomatoes.
7. Chapter 7 – Your First Crop, Week by Week: Day 1 to Week 7 roadmap plus the 30-second weekly inspection routine.
8. Chapter 8 – Problems & Fixes (The 1-Minute Diagnostic): Instant Symptom → Cause → Fix table for root rot, green algae, milky water, tipburn, bolting, and pests.
9. Chapter 9 – Going Further: Float valves, held-level setups for fruiting crops, and staggered weekly harvests.
10. Appendices A to E: Printable Start-Up Checklist, EC/PPM (500 & 700 scale) and US Gallon/Metric conversion tables, Printable Grow Log, Direct links to Dr. Kratky's free papers, and Full Glossary.

Format: Instant PDF Download (38 pages, clean minimalist layout with clear diagrams, readable on phone, tablet, or computer, and ready to print).