Maintaining stable product quality in liquid fertilizers—whether they are liquid biofertilizers, soluble NPK solutions, or customized fluid nutrient blends—depends heavily on accurate control of pH and concentration. These two parameters influence nutrient solubility, microbial activity, shelf stability, and compatibility with irrigation systems. In small- and medium-scale liquid fertilizer plants, improper pH adjustment and inconsistent concentration are among the most common causes of precipitation, fermentation failure, and product degradation.
Why pH Control Matters
Each type of liquid nutrient solution has an optimal pH range. Strongly acidic or alkaline conditions can reduce nutrient availability and may even deactivate beneficial microorganisms in microbial fertilizers. For example, organic extract–based liquid fertilizers often require a mild acidic range to remain stable, while chelated micronutrient solutions perform better in slightly neutral environments. If the pH drifts outside the recommended range, crystallization and sedimentation can quickly appear.
Factors Affecting Nutrient Concentration
Concentration refers to the density of dissolved fertilizer components in the solution. In NPK liquid fertilizer production, too high a concentration increases viscosity and reduces solubility, making the solution unstable during storage. In liquid biofertilizers, excessively concentrated materials can harm living microbial strains. Temperature, water quality, and the mixing sequence all influence concentration consistency. When untreated water is used, minerals such as calcium or magnesium may bond with phosphate, forming insoluble residues.
Practical Methods for pH Adjustment
Producers commonly use mild acids like phosphoric acid or citric acid to lower pH, and potassium hydroxide or ammonia water to increase it. The key is adding them gradually while stirring to avoid sudden jumps. Using a digital pH meter during both mixing and storage helps monitor fluctuations. In organic waste–derived liquid fertilizers, the pH sometimes rises naturally during microbial fermentation. In such cases, controlled aeration and timely nutrient supplementation help keep the pH within a stable range.
Techniques for Managing Concentration Levels
A good practice is preparing a base solution at medium strength, then diluting or enriching it according to product grade. Filtration systems are also essential for keeping the nutrient solution stable. Fine-mesh filters and sediment tanks remove undissolved particles before packaging. For multi-component soluble fertilizers, a sequential dissolving approach—starting with nitrogen sources, then potassium salts, and adding phosphorus last—can significantly improve solubility. Learn more!
Equipment That Helps Stabilize pH and Concentration
Many small liquid fertilizer plants rely on mixing tanks with agitators, metering pumps, and PLC-based dosing systems to maintain precise chemical addition. Stainless steel chelation tanks with constant-temperature control can further prevent salt precipitation during mixing. For organic liquid fertilizers produced from manure slurry, aeration tanks and fine filters ensure that the final product stays clear and uniform. If you need the related machine of adjusting PH, welcome to visit: https://www.liquidfertilizerplants.com/products/automatic-batching-system-for-preparation-of-liquid-fertilizer/
