Evaluation of Humikal Products in a Hydroponic System – Initial Results from a Microgreens Trial

Objective and Design of the Trial

The experiment was conducted between March 23 and April 1, 2026, in the KK2 experimental indoor growing chamber operated by Csillagváros Kft. The system used was a non-recirculating, aerated static water setup based on Kratky/DWC principles. This configuration proved particularly suitable for evaluating nutrient solution stability, the behavior of humic acid components, and direct root zone responses.

The trial involved four plant species:

• sunflower,
• broccoli,
• pea,
• red mustard.

The treatments included:

• control nutrient solution without humic acids,
• Humin Garden+ positive control,
• liquid Humikal,
• Humikal granulate.

The objective was not limited to biomass measurement, but also included evaluating technological manageability, pH and EC dynamics, plant development indicators, and nutritional composition values.

pH Stability: A Key Factor in Hydroponics

One of the most critical parameters in hydroponic cultivation is nutrient solution pH. Significant pH fluctuations can directly affect nutrient availability, root zone performance, and plant growth.

During the experiment, Humikal products behaved similarly to the untreated control, which is considered favorable from a technological standpoint. Particularly noteworthy was that the Humikal granulate maintained pH stability more consistently than the control treatment until harvest, while the Humin Garden+ treatment tended to shift the nutrient solution toward alkalinity.

This is especially important because commercial hydroponic systems typically require acidification to correct elevated pH levels. If a product increases the need for pH adjustment, it may result in additional labor, higher operational costs, and technological instability. Based on this initial study, no such unfavorable effect was observed with Humikal products.

EC Values: No Significant Interference with Nutrient Monitoring

Electrical conductivity (EC) is one of the most important operational indicators in hydroponics, reflecting the concentration of dissolved salts and available nutrients in the nutrient solution.

According to the trial results, Humikal products did not significantly increase EC values compared to the control treatment. This may be particularly advantageous in automated or semi-automated fertigation systems, where EC-based nutrient management is essential. In contrast, the Humin Garden+ treatment resulted in noticeably higher EC values.

From a practical perspective, this suggests that Humikal products may integrate more efficiently into systems where nutrient solution control, dosing precision, and measurement reliability are critical.

Yield Results: Granulate Showed 23–25% Biomass Increase

One of the most important outcomes of the study was the evaluation of total harvested biomass. The combined biomass of the four plant species was assessed from a 0.72 m² cultivation area after a one-week growing cycle.

The results showed that the solid Humikal granulate treatment produced a 23–25% increase in yield compared to the control. The liquid Humikal treatment resulted in a slight biomass increase, while the highest overall biomass values were recorded with the Humin Garden+ treatment.

These findings are particularly significant because in hydroponic systems, product applicability is determined not only by yield performance, but also by technological manageability, sediment formation, cleanability, and nutritional quality.

Potential Reduction in Growing Cycle for Sunflower Microgreens

Based on leaf count and developmental indicators, sunflower microgreens showed more pronounced differences between treatments. Humikal and Humin Garden+ treatments achieved higher developmental values, suggesting the possibility of reducing the cultivation cycle by approximately one day in future production cycles.

In a typical 7–8 day microgreen production cycle, this could represent up to a 12.5% reduction in cycle time.

This is especially valuable in indoor farming systems, where shorter production cycles can directly improve production capacity, shelf utilization, and economic efficiency.

Nutritional Composition: Favorable Mineral Content in Several Cases

One of the key market advantages of microgreens is their elevated mineral and nutritional content. Laboratory analyses covered 12 elements, including potassium, phosphorus, calcium, magnesium, iron, zinc, molybdenum, as well as selected heavy metals.

According to the report, Humikal products helped achieve or approach EU “source of” nutritional claim thresholds for calcium, potassium, and magnesium in several cases.

This is highly relevant because in the functional food and premium microgreen market, value is created not only by production volume but also by nutritional quality.

Food Safety Considerations: Heavy Metals

The study also included heavy metal analysis. According to the report, heavy metal concentrations remained below detection limits in most cases.

Detectable levels of nickel and cadmium were identified in sunflower samples; however, the measured concentrations remained well below concerning thresholds and were considered safe.

This is a particularly important consideration for technologies intended for food production, microgreen cultivation, and indoor farming applications.

Technological Observations: Liquid Form Appears More Suitable for Automated Systems

One of the most valuable aspects of the trial was the collection of practical technological observations.

When mixing the Humikal granulate, a non-soluble sand-like residue remained, which formed a fine sediment layer at the bottom of cultivation trays. Although this did not interfere with the DWC system itself, additional technological optimization may be required for recirculating and automated systems to avoid potential issues involving pumps, valves, and pipelines.

In the case of liquid Humikal, sedimentation was observed at the bottom of the bottle, but this improved after thorough shaking, and no sediment accumulation appeared in the cultivation trays. Based on these observations, the liquid formulation may offer a more practical starting point for integration into automated hydroponic systems.

Conclusion

Based on this first hydroponic evaluation, Humikal products appear suitable for use in DWC systems and demonstrated favorable results across several parameters.

The most important findings include:

• Humikal products did not significantly interfere with EC-based nutrient solution control,
• Humikal granulate demonstrated favorable pH stability,
• the granulate treatment achieved a 23–25% increase in total biomass compared to the control,
• sunflower microgreens showed developmental indicators suggesting the potential for shorter cultivation cycles,
• nutritional composition shifted favorably in several cases,
• heavy metal analyses revealed no concerning levels,
• and the liquid Humikal formulation appeared easier to integrate into automated hydroponic systems from a technological standpoint.

It is important to emphasize that this was an initial trial phase. Further studies will be required to establish precise dosing recommendations, scaling potential, integration into automated systems, and long-term cultivation performance.

However, the results clearly indicate that humic acid-based Humikal technology may hold significant potential not only in field and horticultural cultivation, but also in modern controlled-environment, water-based growing systems.