Phosphate adsorption

Adsorption is defined as the accumulation of substances (in our case, phosphate, silicate, and copper) from gases or substances (in our case, aquarium water from salt water or fresh water tanks) on the surface of a solid. As a result, the substances to be removed remain adhered to the adsorbent's surface. The larger the surface, the more fabrics that can be bound. During absorption, on the other hand, the substances to be removed are bound inside the solid.

The application of a phosphate adsorber keeps the algae growth in the aquarium at bay. How come? Quite simply. Phosphate is an important nutrient for algae growth. The algae can only grow as well as the nutrient with the lowest concentration allows them to (the minimum law). If the phosphate is bound to the adsorber, it is no longer freely available in the water and becomes the limiting factor for algae growth.


ROWAphos is the name of our phosphate adsorber. This is a granulate based on iron. More specifically, an iron oxide hydrate (chem. composition: ß-FeOOH and Fe(OH)3), which binds phosphate, silicate, copper, arsenic, and other heavy metals by chemisorption and thus removes them from the water.

The sensitive water chemistry, especially in the salt water field, has not changed. ROWAphos can therefore be safely used for sensitive lower animals (e.g., SPS corals), fish, and plants. That is why it is also perfectly suitable for use in demanding reef aquariums. The best part is that the phosphate bound by ROWAphos is not released again.

Now, it is frequently copied but never reached. 

We were the first to bring an iron-based, synthetic phosphate adsorber to the worldwide aquarium market. What makes ROWAphos so unique? The recording capacity and, as a result, the power. Both are directly related to the surface of the adsorption material. One kilogram of ROWAphos has a surface as large as the area of 30 football fields.

Liquid turns into a solid!

Another important unique selling point is its purity. The raw materials for ROWAphos are three liquid, pure raw materials: iron (III) chloride, lye, and water. A slightly moist, very high-quality granulate is produced with a lot of know-how and a continuous quality assurance and control system. Since the aquarium market sometimes uses granules that have been produced from waste materials or residues and are preloaded, our ROWAphos is therefore often referred to as "virgin" in English-speaking countries as opposed to "non-virgin" for the preloaded material.

As a material for arsenic removal in drinking water production, it has been the leading product in waterworks worldwide for over 20 years. So it is quite possible that you have water coming out of the pipe that has also been filtered with this adsorption material from Osnabrück.