A passive, non-circulating hydroponic method where plants grow over a nutrient reservoir and roots gradually access both nutrient solution and an expanding air.
Kratky is the simplest pure-hydroponics method.
Troubleshooting
Roots dry out early.
Use a larger reservoir, reduce heat, or top up carefully without eliminating the air gap.
Algae grows in the container.
Block light from reaching the nutrient solution and clean containers between cycles.
Maintenance
Keep containers opaque to limit algae.
Check nutrient level and avoid drowning established air roots.
Use larger reservoirs for longer or thirstier crops.
Make It Yourself
Choose an opaque container or bucket with a lid to reduce algae growth.
Cut holes for net pots and fill the container with nutrient solution to just touch the bottom of the starter plug or roots.
Place seedlings in net pots and avoid topping up fully once roots establish, so an air gap can form.
Monitor water level, pH, and EC, especially for longer crops or warm conditions.
Cost
10 - 100 NZD
Power Consumption
0 - 0 W
Variants
Mason jar Kratky: Small passive system for herbs or leafy greens in jars or small containers.
Bucket Kratky: Larger passive container for single plants such as basil, peppers, or compact tomatoes.
