NITRIFICATION RECOVERY NORWAY, 2021

In 2021, a salmon parr unit in Norway faced significant challenges in establishing effective nitrification in its 650m³ biofilter system. Despite initial attempts with commercial inoculants and modifications such as increased water changes, feeding regime adjustments, and ozone additions, the system struggled with rising ammonia levels, peaking above 7 parts per million (ppm). These high levels indicated a failure in converting ammonia to nitrite or nitrate, stressing the salmon and compromising their environment.

Recognizing the urgency of the situation, the farm's management decided to implement an accelerated start-up protocol using RAS-Right bacteria, advised by their RAS designer. Unlike traditional methods that might involve bio-reactor grow tanks or onsite bacteria cultivation, they opted for a direct application of ready-to-use bottled RAS-Right bacteria to the Fixed-Bed Bioreactor (FBBR). This approach allowed for a large initial dose followed by smaller, ongoing doses to ensure a robust population of nitrifying bacteria.

The intervention was a success, stabilizing nitrification within just 11 days of the first treatment, achieving TAN and Nitrite levels below 0.5ppm and observing rising Nitrate levels. This outcome not only resolved the immediate crisis of high ammonia levels but also established a sustainable method for managing water quality, thus ensuring the health and growth of the salmon in the facility.

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