Kratky Hydroponics FAQ
Short answers to the questions beginners ask most. Each answer links to the lesson that covers it in full.
What is the Kratky method?
Growing a plant in a closed container of nutrient solution with no pump. As the plant drinks, an air gap opens and the upper roots breathe from it. How the Kratky Method Works
What should I grow first?
Leaf lettuce. It is fast, small and usually finishes on one fill of solution. Choose Your First Kratky Plant
Do I need a pump or electricity?
No. The only thing you might plug in is a grow light. Gather Your Kratky Supplies
Can I use a mason jar?
Yes, if you block light from the solution. A quart jar suits one lettuce plant picked young. Pick a Kratky Container
Can I use regular garden fertilizer?
Usually not. Use a nutrient made for hydroponics, which supplies the nutrients soil normally provides. Mix the Nutrient Solution
What pH should the solution be?
About 5.5 to 6.0 suits most beginner crops. Adjust it after mixing in the nutrients. Check and Adjust pH
How full should I fill the container?
Until the solution just touches the bottom of the net cup. Not higher. Set Up and Transplant
Is a window bright enough?
Sometimes in the brighter months. If plants stretch and look pale, add a grow light. Light and Location
Should I refill the container as it drops?
No. The falling level creates the air gap. If it runs low before harvest, top up only to the lower roots. Weekly Checks and the Air Gap
When do I harvest lettuce?
Pick outer leaves as soon as they are big enough, or cut the whole plant before it starts to stretch and turn bitter. Harvest Your Kratky Plants
Why are my roots brown and slimy?
Usually root rot from warm solution, a light leak or overfilling. Start again with a clean container. Fix Common Kratky Problems
Can I grow tomatoes with Kratky?
Yes, with a large container, regular careful topping up and support. Dwarf varieties are the easiest start. Next Step: Fruiting Plants
Can I grow strawberries with Kratky?
Yes. Use day-neutral plants, keep the crown above the solution and pollinate the flowers by hand indoors. Grow Strawberries with Kratky