Why is sodium humate called the "Black King Kong" of water treatment?

Sodium humate has been widely used in aquaculture. Its application is as indispensable as zeolite powder and quicklime. Experienced aquaculture workers are familiar with it. It is very dark, almost shiny black, highly water-soluble, and has remarkable water conditioning effects. Let's briefly understand some of its aspects: the application and mechanism of sodium humate in aquaculture.

I. The main effects of sodium humate in aquaculture are as follows:
(1) Water fertilization: The early application of sodium humate in aquaculture originated from its fertilizer properties in agriculture. According to relevant data, sodium humate has a high carbon content, approximately 50%-60%, and after decomposition, it is a superior carbon source fertilizer. Used for water fertilization, it stimulates rapid algae growth without causing eutrophication like some inorganic fertilizers.
(2) Physical sunshade: After applying sodium humate to the aquaculture water body, the water color deepens, and the transparency decreases. This can block some sunlight from reaching the bottom, thus preventing algae growth. It is used extensively in crab farming ponds. In practice, powdered products persist in the water body for a shorter time, generally 1-3 days, while flake products persist for a longer time, generally more than 5 days.
(3) Water purification: Sodium humate is a relatively stable natural macromolecular organic substance with an aromatic structure, composed of a discontinuous network of sparsely connected aromatic rings. Its structure contains many pores and cavities of varying sizes, resulting in a large internal surface area and strong adsorption, exchange, complexation, and chelation capabilities. It also contains multiple effective components. Through physical and chemical actions, it adsorbs and aggregates organic matter and suspended solids in the water, integrates heavy metal ions, and oxidizes toxic substances such as ammonia nitrogen and hydrogen sulfide in the water body. The porous gaps, on the one hand, purify the water quality, and on the other hand, provide a good breeding ground for beneficial microorganisms. Using the adsorption and complexation characteristics of sodium humate can help treat common aquaculture water quality deterioration situations such as turbidity, bottom sediment problems, dead algae, oil films, and excessive foam.
(4) Chelation of heavy metal ions: The surface of sodium humate carries a large negative charge, and its molecular structure contains many carboxyl and phenolic hydroxyl groups. Therefore, it can react with heavy metal ions in water. The adsorption of heavy metal ions is not only cation exchange but also chelation, effectively reducing the harm of heavy metal ions to farmed animals.
(5) Improvement of substrate and detoxification and deodorization: The mesh-like and porous structure of sodium humate can loosen the soil, improve the permeability of the substrate, and adsorb some NH3 and H2S in the bottom environment, thus removing the odor of bottom sediment and reducing environmental pollution.
II. How to judge the quality of sodium humate? The quality of sodium humate mainly depends on the humic acid content. High-quality sodium humate has a humic acid content as high as 60% and an organic matter content of 70-80%, while some manufacturers' products only contain 20-30% humic acid. Secondly, water solubility is important; only sodium humate with good water solubility can exhibit good effects in water. Aquaculture users do not have the conditions to test the humic acid content when purchasing sodium humate products. Some users rely on experience to judge the quality of sodium humate, mostly by judging the product quality through the depth of color, water solubility speed, and feel. However, this method is not scientific or professional because everyone's senses are different, and subjective factors are too great, resulting in large errors in the results. A better method is to purchase sodium humate products produced and sold by regular manufacturers, so that the product quality can be guaranteed.
III. What is the difference between sodium humate and humic acid? Humic acid is acidic, with a pH of 4-6 depending on the type, and generally has low water solubility. Sodium humate is a product obtained from the reaction of humic acid with sodium hydroxide. It is alkaline, with a pH of 9-10, and is more easily soluble in water. Therefore, sodium humate is more commonly used in aquaculture.
IV. Precautions for using sodium humate
(1) Do not mix with drugs that are incompatible with alkaline substances.
Because sodium humate is an alkaline substance, the pH of pure sodium humate is 9-10.
(2) Do not mix with organic acids
Sodium humate is alkaline. In practical applications, do not mix it with acidic substances, especially organic acid products.