Price per kg does not always mean savings: the case of catalytic media for iron and manganese removal
3 min read
In increasingly competitive markets, it is common for many consumers of catalytic media to seek the lowest price per kg as the primary criterion when choosing a catalytic filter media for iron and manganese removal. But is this really the best way to compare?
Behavioral science teaches us that human beings, when making decisions under uncertainty, tend to cling to numbers that are easy to understand — such as price per kilogram — even when other factors are more relevant to the result.
Let’s illustrate this with a practical, real-world example:
Technical and economic comparison between two catalytic filter media
The surprise: the cheapest product per kg is the most expensive per liter.
Product B seems cheaper at first glance, with a value of R$ 12/kg against R$ 15/kg for Product A. But when we consider what really matters in practice — the volume needed to fill the filter — we realize that Product B is 52% more expensive per liter of occupied volume.
This happens because Product B is denser (1,9 kg/L), and therefore occupies less volume per kilogram. In other words: it will be necessary to buy more kilograms of Product B to fill the same volume in the filtration system.
What really matters in sizing?
In most filtration systems — whether in water treatment plants, artesian wells, or industrial processes — what is sized is the volume of media (in liters) and not the weight. Therefore, the correct analysis for decision-making must consider the cost per liter.
Smart decision: breaking the “cheapest per kg” bias
This is a classic example of what behavioral science calls “simplification bias”: we make decisions based on a single, easily accessible number (R$/kg), ignoring critical variables such as density, yield, and effective volume.
By bringing this type of analysis to our clients, we are promoting not only a more consultative sale but also educating the market to make smarter and more sustainable decisions.
Conclusion
When choosing your catalytic filter media:
Do not compare only the price per kg.
Evaluate the cost per installed liter.
Think about performance, service life, and volumetric efficiency.
The best choice is not always the cheapest per kg — but rather, the one that delivers the best result per real invested in the useful volume of the filter.
If this topic makes sense to you or your company, let’s talk. I am available to help with the technical and economic analysis of your filtration system.
