If your fish are dying right now, every minute matters. This guide gives you the exact steps to take in the next 30 minutes, the next 2 hours, and the next 24 hours — based on real Nigerian catfish farming conditions.
Oxygen depletion kills faster than any disease. The moment you see fish gasping at the surface or dying, your first action is oxygen — not diagnosis, not medication.
Every aerator, every paddle wheel, every air stone you have — turn them all on now. If you have a generator, use it. Do not wait for electricity.
Use a bucket, a stick, or anything to agitate the water surface. This is not ideal but buys you 15–20 minutes while you get the aerators running. Any movement at the water surface increases oxygen exchange.
Fresh incoming water brings oxygen. If you have a borehole or water source, open it and let fresh water flow in while you prepare for a water change.
Remove 30–50% of pond water and replace with clean fresh water. This single action reduces ammonia, refreshes oxygen, lowers bacterial load, and dilutes any toxins. It works regardless of what disease is present.
While the water change is happening, observe your fish carefully. The symptom pattern tells you which disease you are dealing with.
| What You See | Most Likely Cause | First Treatment |
|---|---|---|
| Gasping at surface, pale gills | Gill Rot or low oxygen | Aeration + 2–3g/L salt |
| Body ulcers, red patches, bloating | Aeromonas (MAS) | Salt + Oxytetracycline |
| White cotton patches on back/fins | Columnaris or Fungal | 3g/L salt + KMnO₄ |
| Frayed fins, eating reduced | Fin Rot | Water change + 2g/L salt |
| Spinning, loss of balance | Bacterial septicemia | Emergency antibiotic |
| All fish hiding, no feeding | Water quality crash | Massive water change |
Salt is your universal first-line treatment. It works against bacterial and fungal infections, reduces osmotic stress, and buys time while you get the right medication.
Pond volume (litres) × target dose (g/L) = total salt needed (grams)
Example: 10,000 litre pond at 3g/L = 30,000g = 30kg of salt
Dissolve salt in a bucket of pond water first, then pour slowly around the pond edges. Never dump dry salt directly on fish.
Use iodine-free table salt or agricultural salt. Iodine kills fish at high doses.
Dead fish decompose within hours in warm Nigerian water, releasing massive quantities of ammonia, bacteria, and disease spores. Remove every dead fish you find and either bury them at least 50cm deep or burn them. Do not throw in open drains or nearby water sources.
Establish a twice-daily dead fish removal routine for the duration of the outbreak — 6am and 6pm.
After the emergency water change and salt treatment, assess the situation. Are fish still dying rapidly? Is mortality slowing? Based on your symptom identification in Step 3, proceed to the specific disease treatment page:
Describe exactly what you see to MyFishDoc AI Doctor. It knows your pond data and will tell you exactly what disease it is and what to do — even at 2am.
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