Hydroponics and Vertical Farming: The Technical Guide to Understand, Grow, and Innovate

11. How to properly prepare the nutrient solution in hydroponics

Written by Tomato+ Team | Nov 22, 2025 10:53:33 AM

 

1. What is really the nutrient solution

In hydroponics, the nutrient solution replaces the soil: it is water + mineral nutrients dissolved in the right proportions.

Its task is:

  • provide macroelements (N, P, K, Ca, Mg, S)

  • provide microelements (Fe, Mn, Zn, Cu, B, Mo, etc.).

  • maintain pH and EC in the optimal ranges for the species grown

  • be stable over time, without precipitation or imbalance

A poorly prepared solution immediately causes:

  • slow growth

  • discolored leaves

  • suffering roots

  • lower yields

2. Minimum equipment needed

  • Starting water (low hardness is best)

  • Fertilizers A + B for hydroponics

  • EC meter

  • pH meter

  • pH- and pH+

  • Graduated canister or container

  • Graduated cylinders or syringes

  • Aerator (if the solution remains stationary in the tank)

3. Water: the starting point

Water quality conditions everything.
With hard water you risk:

  • high pH

  • excess Ca/Mg

  • precipitation

Solutions:

  • use osmotic water

  • or mix mains + osmotic

The "cleaner" the water, the more you control the solution.

4. Because fertilizers are divided into A + B

  • Solution A → calcium + trace elements

  • Solution B → phosphorus + sulfates

Never mix them concentrated.
Dilute in water first, then add them to the tank.

5. How to prepare the nutrient solution (step-by-step).

5.1 Define target EC and pH

  • Salads: 1.2-1.8 mS/cm

  • Basil: 1.4-2.2 mS/cm

  • Tomatoes and fruiting vegetables: 2.0-3.0 mS/cm

  • Ideal pH: 5.5-6.5

In advanced systems such as Horto Professional, sensors and AI support continuous monitoring of parameters.

5.2 Fill the tank

  • Clean the tank

  • Fill almost to final volume

  • Measure initial EC and pH

5.3 Add fertilizers A + B

  1. Shake the bottles

  2. Add A first, then B

  3. Mix

  4. Measure EC

    • Low EC → add fertilizer

    • EC high → add water

5.4 Correct pH

  • pH too high → add pH- in small doses

  • pH too low → add pH+

Always small steps, always mix and measure.

5.5 Oxygenation and stabilization

  • Let recirculate for 15-30 minutes

  • Recheck EC and pH

If solution stands still for days → maintain good oxygenation.

6. Frequency of solution change.

Depends on volume, system and consumption.

Rule of thumb:

  • daily check of EC and pH

  • frequent partial changes

  • total replacement every 7 to 14 days

In professional systems such as Horto Professional, management is automated.

7. Common mistakes to avoid

1. Mixing concentrated A and B
→ Precipitation.
✔ Always add in water, one at a time.

2. Do not measure EC and pH
→ unstable cultivation.

3. Water too hard
→ nutritional blockages.

4. Changing too many parameters together.
→ impossible to figure out what worked.

5. Neglected water temperature.
→ above 24-25 °C increases pathogen risk.

8. How Tomato+ simplifies your life.

Tomato+ greenhouses completely reduce the operational complexity of hydroponics:

  • Compostable pods include seeds and substrate optimized for each crop.

  • Over 100 varieties already tested, with no need to create nutrient recipes from scratch.

  • In professional versions, sensors, automations and AI manage light, irrigation and parameter monitoring in real time.

➜ Integration on Horto2 and Horto4.

In Horto2 and Horto4 greenhouses, preparing the nutrient solution is even easier:
just fill the tank with demineralized water and add a predosed granular solution.
This unique formulation automatically establishes the correct EC and pH values for all Tomato+ crops, eliminating dosing errors and ensuring consistent results even for beginners.
Zero calculation, zero tools-the greenhouse does the rest.

9. A process, not a gesture

Preparing the nutrient solution is a precise and repeatable process.
By following a clear routine-controlled water, regular measurements, micro changes-you get a stable and productive crop.

And if you want a system that automates everything, Tomato+ allows you to go from improvisation to professional, uncomplicated cultivation.

Thank you for reading this article. Keep following us to discover new content on hydroponics, vertical farming, and smart farming.
Tomato+ Team