Kratky Nutrient Solution: How to Mix, Measure and Maintain It
Kratky Nutrient Solution is a plain-English guide to the one thing a Kratky system depends on: the water and nutrients your plants sit in. There are no pumps, air stones or timers in the Kratky method, so the solution you mix on day one has to carry the plant through most of its life. Getting it right is most of the work.
What this site covers
- What a complete hydroponic nutrient contains, and why garden fertilizer is not a substitute
- How to mix a solution from one-part and two-part nutrients
- How strong the solution should be, measured as EC or PPM
- Checking and adjusting pH
- When to top up and when to start over with fresh solution
- Reading leaf symptoms that point to a nutrient problem
Why the solution matters more in Kratky
In a Kratky container, the plant drinks the solution down over time. As the level falls, an air gap opens between the lid and the water, and the upper roots use that gap to breathe. Because nothing circulates or refreshes the water, any mistake made at mixing time stays in the container: too weak and the plant runs short before harvest, too strong or at the wrong pH and growth stalls early.
The basics in brief
- Use a nutrient made for hydroponics. It supplies calcium, magnesium and trace elements that soil normally provides.
- Add each part to the water separately. With two-part nutrients, stir part A into the water before adding part B. Never mix the concentrates together.
- Follow the label rate, then measure. An EC or TDS meter tells you the actual strength. Leafy greens generally want a weaker solution than fruiting plants.
- Check pH after mixing. Most crops do well between about 5.5 and 6.5.
- Do not refill to the top once roots have an air gap. Submerging the air roots can drown them. Add a smaller amount instead.
Who it is for
Home growers using jars, buckets or totes, whether you are setting up a first container or trying to work out why a plant has turned pale or stopped growing.
