Kratky Nutrient Solution FAQ

Short answers to the questions growers ask most often. Each answer links to the guide that covers it in full.

What is a Kratky nutrient solution?

Water with a complete hydroponic nutrient dissolved in it, mixed once before planting. The plant lives on that single batch until harvest. Nutrient solution basics.

Can I use regular garden fertilizer?

Usually not. Most garden fertilizers rely on soil to supply calcium, magnesium and micronutrients. Use a nutrient labelled for hydroponics. Why garden fertilizer falls short.

Should I buy a one-part or two-part nutrient?

Either works. One-part is simplest. Two-part keeps calcium separate so it does not react in the bottle; just add each part to the water separately. Choosing a nutrient.

Can I use tap water?

In most cases, yes. Measure its EC and pH first. Very hard or softened water needs extra care. Water for Kratky solution.

In what order do I add the nutrients?

Add each part to the full volume of water, stirring between parts. Set the strength first, then adjust pH last. How to mix Kratky solution.

What EC should I use for lettuce?

Oklahoma State University Extension lists 1.2–1.8 mS/cm for hydroponic lettuce. UF/IFAS suggests about 1.25 mS/cm for Kratky greens. EC and PPM targets.

Why does my PPM reading not match the chart?

PPM meters use different conversion scales. The same solution can read 500 ppm on one meter and 700 ppm on another. EC is the same on every meter. EC and PPM explained.

What pH should Kratky solution be?

About 5.5 to 6.0 suits most Kratky crops. pH for Kratky solution.

Can I use vinegar to lower pH?

Yes. White vinegar lowers pH; UF/IFAS notes it typically takes around 2 teaspoons per gallon, depending on the water. Add a little at a time and retest. Adjusting pH.

Should I top up my Kratky container?

Ideally not; size the container to last the crop. If you must, add only enough to reach the lower roots and never refill to the top. Topping up without drowning roots.

Can I grow tomatoes with the Kratky method?

Yes, but they need a much larger container and regular, careful topping up over several months. Solution by crop.

Why are my leaves turning yellow?

Yellow older leaves often mean the solution is weak or low in nitrogen; pale new leaves often mean pH is too high. Measure EC and pH first. Problems and fixes.

What equipment do I need?

A complete hydroponic nutrient, a way to test pH, pH down, measuring tools and a lightproof container. An EC meter is strongly recommended. Supplies list.