Fishmeal prices have nearly doubled in a year and global supply is at its lowest since 2016. Fish farmers are being forced to look to cheaper plant protein alternatives such as soybean meal. These come with hidden costs, especially in RAS systems:
Density effect: under the same conditions, these symptoms worsen at higher stocking densities.
Plant protein ingredients are less digestible, meaning more waste is excreted by the fish causing dissolved organic carbons (DOCs) to build up much faster in RAS water.
Our on-farm trials have shown the symptoms above are a result of dissolved organic carbons (DOCs) accumulating in the system water. As they accumulate, they quietly degrade water quality, fish health and ultimately fish growth performance.
Digestive metabolites produced in the fish gut and the system biofilm build up quickly in RAS water due to low water replacement rates. They accumulate as a mixture of many different types of dissolved organic carbon molecules (DOCs) smaller than 0.45µm. These organic compounds are re-absorbed into the fish flesh via the gills and accumulate to the extent that they give it an off-flavour. The compounds also seem to negatively affect fish physiology and endocrinology, harming their health and growth performance.
The compounds include Phenol, 1,3-Benzothiazole, 2,3,5-Trimethylpyrazine, 2-MIB, Geosmin and many others.
To date, their detection and management in RAS has been difficult due to the limited sensitivity of laboratory testing equipment. Human aroma detection (smell) is still the most effective tool used in off-flavour research today.
The CarbonClear process uses food-safe, custom-made, powderized activated carbon to bind and remove dissolved organic carbons in a fundamentally more effective way.
Here’s how to find out and what to do about it.
Send a water sample to your closest laboratory and ask them to test for dissolved organic carbon.
You have two options.
If you use an established international feed supplier, it is likely they already know about CarbonClear. Reach out to them to find out more. Introduce us if not and we’ll guide them through the process.
The CarbonClear process is protected by international intellectual property rights agreements.
If you want advice, further information or exclusive licensing for product development in your area, please reach out either over WhatsApp or by filling out the email form below.
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