High NO2 (Nitrite toxicity)
High NO2 (Nitrite toxicity) — Caused by accumulated feces, excess feed; disrupted nitrification (NH3 → NO2 → NO3); lack of beneficial microbes or dirty bottom.
Symptoms
NO2 > 0.5 ppm: appetite loss, surfacing, red body. NO2 > 2 ppm: purple gills, scattered mortality (methemoglobin syndrome).
Risk Level
Highly toxic — NO2 blocks oxygen transport in shrimp blood. NO2 > 5 ppm → mass mortality within 24-48h.
Treatment Protocol
1. Maximum aeration 24/7.
2. Seed NO2-reducing probiotics: MAX 4000 — 1 pack (227g)/1,500m³ water, broadcast 3-5 consecutive days.
3. Bottom treatment: AQUA BLOCK 1kg/1,000m³ or SOILMAX 1 pack/1,500m³.
4. Reduce feeding 30-50% until NO2 < 0.5 ppm.
5. Minerals, anti-stress: GROWMIN, VIMIX.
6. Maintenance: MAX 4000 1 pack/2,000m³ every 3-5 days.
👉 Details: https://thanvuong.vn/en/solutions/high-no2
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FAQ
What is High NO2 (Nitrite toxicity)?
Caused by accumulated feces, excess feed; disrupted nitrification (NH3 → NO2 → NO3); lack of beneficial microbes or dirty bottom.
Symptoms of High NO2 (Nitrite toxicity)?
NO2 > 0.5 ppm: appetite loss, surfacing, red body. NO2 > 2 ppm: purple gills, scattered mortality (methemoglobin syndrome).
Is High NO2 (Nitrite toxicity) dangerous?
Highly toxic — NO2 blocks oxygen transport in shrimp blood. NO2 > 5 ppm → mass mortality within 24-48h.
How to treat High NO2 (Nitrite toxicity)?
1. Maximum aeration 24/7. 2. Seed NO2-reducing probiotics: MAX 4000 — 1 pack (227g)/1,500m³ water, broadcast 3-5 consecutive days. 3. Bottom treatment: AQUA BLOCK 1kg/1,000m³ or SOILMAX 1 pack/1,500m³. 4. Reduce feeding 30-50% until NO2 < 0.5 ppm. 5. Minerals, anti-stress: GROWMIN, VIMIX. 6. Maintenance: MAX 4000 1 pack/2,000m³ every 3-5 days. 👉 Details: https://thanvuong.vn/en/solutions/high-no2