Erratic swimming or spinning
This looks like: ammonia/nitrite poisoning, temperature shock, or swim bladder congestion — test water before blaming food
Why this happens
Neurological distress shows as loops. Ammonia hurts the brain; constipation tips balance organs.
How sure are we? Split — water tests split the difference in minutes.
What to do right now
- Test ammonia and nitrite — if >0, large volume of matched dechlorinated changes until clear.
- Check temperature consistency heater-to-heater.
- If tests clean and fish is deep-bodied goldfish-type: try shelled pea diet after fasting 24h — not for every species.
- Lower flow temporarily if fish get thrown around physically.
- Stop adding salt randomly — measure if you truly need it.
What not to do
- Don’t crank heat to “fix” swim bladder without confirming diagnosis.
If that doesn’t fix it
Persistent corkscrewing in livebearers warrants differentials — photo and timeline help.
Catch this earlier next time — log your water parameters in App-aquatic. Free forever.