What are the benefits of humic acid

Humic substances in the aquarium

Humic substances act as supporting elements on fish, invertebrates and plants in an aquarium. In fact, the importance of humic substances in aquaristics is still rather underestimated, and many simply associate them with annoying brown colored water. In this article on our Aquascaping Wiki, we explain what exactly these humic substances are all about.

Definition of humic substances

Humic substances are first and foremost components of humus, which is the entire organic, decomposing substance of the soil. The microorganisms living in it constantly convert the components of the humus and continue to break it down in this way. Humic substances represent various complex macro-molecules as a component of this soil. The structure of such a molecular complex is not uniform and sometimes even changes depending on location and season. In their basic structure, humic molecules consist of a core (often consisting of furan, benzene, pyrrole, pyridine, naphthalene, indole or quinoline), bridges (often these contain carbon, oxygen or nitrogen), as well as side groups (mostly amino, carboxy , Methoxy, carbonyl and hydroxyl groups).
In general, the components of humus, i.e. the humic substances, can be divided into humins, fulvic acids and humic acids.

Humic substances occur almost everywhere in nature and are not only present in practically every ecosystem (on land or in water), but also play an important role. This in turn means that living beings such as fish, shrimp, snails and also plants that we want to keep in our aquarium have already got used to humic substances in their original habitats and have learned to "use" them.

Humic substances in tap water

Humic substances (for humans) are rather undesirable in our drinking water or tap water, so they are filtered out by the drinking water treatment. So if you use tap water for your aquarium, it does not contain any humic substances. Even when using demineralized water (e.g. from an osmosis system) and hardening salts, no humic substances get into the aquarium. If the aquarist wants to use the advantages of humic substances, he must therefore supply them with appropriate preparations.

Advantages of humic substances in the aquarium hobby

As is now known, humic substances in aquarium water have both direct and indirect effects on the inhabitants of the aquarium. While it was unclear for a long time what (especially direct) effects humic substances have on living beings, these are now scientifically proven.

In the wild, humic substances play a very important role in making hostile conditions usable for aquatic organisms at all. Take, for example, very acidic and soft waters such as the Rio Negro. The water here is very poor in minerals and sometimes has a pH value of only 3 or 4. In such an environment, animals would normally not be able to survive at all or only with great difficulty. It is only through the use of humic substances that living beings in such waters are able to accumulate enough vital minerals, such as calcium for building bones. Humic substances are therefore even vital for the care of animals that come from such black water habitats in the aquarium, as they have adapted very strongly to the presence and use.

Antibacterial effect of humic substances

Another point, why humic substances have been used in fish farming for a long time, is their antibacterial and fungicidal effect. This prevents spawning fungus and the adults also benefit from a sterile environment. The likelihood of an infectious disease due to a fungal attack also decreases when using humic substances. This is achieved by the fact that these substances create a kind of protective film both on the skin and in the digestive tract of the animals. The docking points for pathogens are occupied by humic substances, so that fewer germs have the chance to penetrate an organism.

Improved healing process

However, if a clinical picture (such as fin rot, white spot disease, mold infestation) occurs among the aquarium inhabitants, humic substances can support the healing process. They have anti-inflammatory effects, stimulate mucosal production in fish and can even stop or slow bleeding. In the gastrointestinal tract, the toxins produced by pathogens are bound and the reproduction of pathogens is curbed. However, the preventive use of humic substances in the aquarium is far more effective so that an acute disease does not develop in the first place.

Strengthening the immune system

Humic substances improve the immune system of the aquarium animals. The presence of humic substances puts living beings in a mild chemical stress state. However, similar to a vaccination in mammals, this has a completely positive effect: the immune system is challenged and thus strengthened. As a result, the animals can develop multiple stress resistances, some of which can have a life-prolonging effect. This is the case, for example, with studies on nematodes Caenorhabditis elegans surrender. Some studies have also shown positive effects of humic substances on fertility and the growth of living things. This has been done by experiments with the swordtail Xiphophorus helleri confirmed, in which young fish and embryos showed improved growth through the addition of a preparation containing humic substances[1]. Also with other types of fish such as Perca flavescens a better hatching rate could be demonstrated with a higher humic content in the water[2].

Promote digestion

Humic substances in the intestine of an animal are able to bind toxins and heavy metals that occur there. This supports the intestinal flora of the animal and helps with digestion. The protective film on the intestinal wall, which is created due to the humic substances, fends off chemical and microbial stimuli. A healthy gastrointestinal tract means that food can be optimally chopped up and absorbed.

Reducing stress

As already explained under the section "Strengthening the immune system", humic substances put living beings into a minimal chemical stress state, which means that they react with appropriate defense mechanisms. Similar to a vaccination, this has the effect that the animals are much better prepared for a real stressful situation. In this way, multiple stress resistances can develop, which result in more persistent and stable animals.

More general effects of humic substances in the aquarium

Humic substances in aquariums also have positive effects on the water values. They act as a natural buffer and stabilize the pH value in this way. In very soft water with extremely low carbonate hardness, an acid fall is avoided.

For aquatic plants, humic substances are also beneficial for growth and nutrient uptake. They act as a natural chelator and thus increase the availability of important nutritional elements such as iron and copper. Due to the improved mineralization and degradation processes in the soil due to the presence of humic substances, macronutrients such as nitrogen and phosphorus are also more easily available. In addition, humic substances have the ability to function as cation exchangers, which optimizes the good availability and exchange of cations and thus nutrients such as potassium, calcium and magnesium.

How to add humic substances to the aquarium?

For the aquarium hobby there are a lot of (natural) products that can add humic substances. Alder cones, sea almond products or various types of foliage are particularly popular in aquariums with shrimp or crabs. Here, however, the concentration of humic substances is not particularly high, and the products should therefore be renewed or replaced regularly. Corresponding liquid preparations that contain a full range of concentrated humic substances are much more productive. These are added weekly as maintenance products for water maintenance in the aquarium, ideally after changing the water.

Some soil substrates also contain, at least in part, certain humic substances, such as some environment soil, which contains fulvic acids. In the long term, however, the addition of humic substances through a liquid preparation such as Liquid Humin + is more constant, more predictable and more productive.

Brown water due to humic substances

It is well known that humic substances color the water in the aquarium brown. Sometimes this is also desirable, for example if the aquarist wants to create a black water biotope with the most natural parameters possible. For living beings that come from habitats that are very rich in humic substances, the presence of these elements is sometimes essential because they are very strongly adapted to humic substances.

If you want to use the advantages of humic substances for your community tank, aquascape, plant aquarium or other types of aquaristics, but prefer to keep clear water, you can rest easy. Even a small dose of a humic preparation, which does not color the water so clearly brown, is already an enrichment and a sensible care additive for the inhabitants in the aquarium.

1. Steinberg / Menzel humic substances - dead material highly active. Studies on vital brown geopolymers in aquaristic trade magazine No. 206 April / May 2009 ISSN 1437-4854
2. Bertolo, A. & Magnan, P. (2007): Logging-induced variations in dissolved organic carbon affect yellow perch (Perca flavescens) recruitment in Canadina Shield Lakes. Can. J. Fish Aqu. Sci. 64: 181-186