Hydroponics often sounds complicated — pumps, pipes, air stones, electricity, timers… but what if you could grow nutrient-dense lettuce, basil, spinach, and even tomatoes with no electricity and almost no maintenance?
That’s exactly what the Kratky Method offers.
Invented by Dr. Bernard Kratky at the University of Hawaii, this is the simplest, purest form of hydroponics: no pumps, no wiring, no moving parts — just water, nutrients, and a plant.
In this guide, we’ll cover:
✅ What the Kratky Method is
✅ A simple step-by-step setup
✅ Best crops to grow
✅ Tips to maximise yields
✅ Photos and diagrams
✅ GrowFolk products you can use to build your system
Let’s dig in!
🌿 What Is the Kratky Method?
The Kratky Method is a “set-and-forget” passive hydroponic technique where plants grow in a container filled with nutrient solution. As they consume the water, the level naturally drops, creating an air gap for oxygen. This eliminates the need for air pumps.
Here’s the basic idea:
- A plant in a net pot sits in a lid above a nutrient-filled reservoir.
- The bottom of the net pot touches the nutrient solution.
- As the plant grows, water levels drop.
- Roots naturally divide into:
- Water roots → inside the reservoir
- Air roots → in the open air gap
- The system runs itself until harvest.
This makes Kratky perfect for beginners, home growers, classrooms, urban gardeners, and low-maintenance setups.
🛠 How to Build a Kratky System (Step-by-Step)
You need only a few items — most of which you can get directly from GrowFolk.
1. Choose Your Container
Any bucket, tub, jar, or storage container works.
Recommended:
- 10–20 L buckets for lettuce/herbs
- 20–40 L buckets for tomatoes/peppers
- Jars or 1–2 L tubs for small herbs or propagating plants
Dark containers prevent algae — or simply wrap them in black plastic.
2. Prepare the Lid and Net Pot
Cut a hole in the lid so the net pot fits securely.
GrowFolk product to use:
🔗 Net Pot 75 mm With Lip
https://growfolk.co.za/product/netpot75cmwithlip/
These provide great root aeration and stability.
3. Add a Growing Medium
The net pot needs a lightweight, inert medium.
GrowFolk product to use:
🔗 VitaLink Clay Pebbles (LECA)
https://growfolk.co.za/product/vitalink-clay-pebbles/
Fill halfway into the net pot, pack your seedling in, then top up.
4. Mix Your Nutrient Solution
Fill the reservoir with water and add hydroponic nutrients.
GrowFolk product to use:
🔗 Hydroponic Soluble Nutrients (Complete Formula)
https://growfolk.co.za/product/hydroponic-soluble-nutrients-fertiliser-complete/
General nutrient targets for leafy greens:
- EC: 1.2 – 1.6 mS/cm
- pH: 5.5 – 6.2
Fill the reservoir until the bottom 1–2 cm of the net pot touches the nutrient solution.
5. Insert Your Plant
Start with seedlings grown in:
- Rockwool
- Peat plugs
- Jiffy pods
- Sponge cubes
Make sure roots are reaching the solution.
6. Leave It — No Pumps Needed
As the plant grows:
🌊 Water level drops
🌬 Air gap forms
🌱 Roots adapt automatically
You may never need to top up until harvest.
This is why the Kratky Method is legendary among low-maintenance growers.
🌻 What Grows Best in a Kratky System?
⭐ Top-Performing Crops
These plants thrive in Kratky:
🥬 Leafy Greens
- Lettuce (all varieties)
- Spinach
- Kale
- Bok choy
- Rocket (arugula)
- Swiss chard
🌿 Herbs
- Basil
- Mint
- Coriander (cilantro)
- Parsley
- Thyme
- Oregano
- Chives
🧅 Fast growers
- Spring onions
- Microgreens
🌶 Growable With Large Reservoirs
These work well if you use bigger containers:
- Cherry tomatoes
- Chillies
- Peppers
- Strawberries
Just ensure:
- Larger reservoir (20–40 L)
- Strong support stakes
- Slightly higher nutrient EC
❌ Not Recommended
- Carrots
- Beetroot
- Potatoes
- Large melons or pumpkins
These root-heavy crops don’t suit passive hydroponics.
⭐ Pro Tips for Success
🟢 Use light-proof containers (to prevent algae)
🟢 Keep nutrient temperature below 24 °C
🟢 Check pH once a week for best results
🟢 Place in strong light or use LED grow lights
🟢 Sterilise buckets between cycles
🧰 Build Your Own Kratky Kit (GrowFolk Products)
Below is a ready-made shopping list for GrowFolk customers:
✔ Net Pot 75 mm With Lip
✔ VitaLink Clay Pebbles / LECA
✔ Hydroponic Complete Nutrient Formula
Recommended extras (optional):
- pH Up / Down
- pH Test Kit or digital pen
- Buckets with lids
- Measuring syringes
If you want, I can turn this into a special GrowFolk Kratky Starter Kit bundle.
📦 Example Kratky Setups (Images)
🎉 Final Thoughts: The Easiest Hydroponics System in the World
The Kratky Method is hands-down the easiest way to grow fresh food at home.
- No pumps
- No electricity
- No timers
- No complicated plumbing
- Minimal maintenance
Whether you want crisp lettuce on your patio, herbs in your kitchen, or a few hydroponic tomatoes, Kratky is a robust, proven method that works.
Everything you need to get started is available right here at GrowFolk — affordable, simple, and beginner-friendly.
