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Why is my fish sick, not eating, gasping, and darting in its tank?

Updated On September 23rd, 2025

Pet's info: Fish | Tropical Fish | Male | 6 months and 9 days old | 0.9 lbs

My fish is acting sick. He is not really eating and he keeps going to the surface to breathe . He is also getting these little what looks like panic attacks and swims very fast and even hits his head constantly on the edges of his tank. I started to clean his tank more to see if it helps but it doesn’t . What’s wrong ?

1 Answer

Most Helpful Answer

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Answered By Angel Alvarado, LVT

Licensed Veterinary Technician

Published on March 11th, 2020

Check water chemistry first. Use a home test kit or submit a water sample for testing. The local Petco may do this for free or for a small fee. Aim for an absence ( 0 ppm) of ammonia and nitrites with nitrates at 20 ppm or less. Perform partial water changes, no more than 30% at a time, to stabilize chemistry and/or to improve water quality. Use only conditioned water that is temperature matched to prevent stress or shock. Check water temp as well. Any of these can drive a fish to the surface. The "flashing" (darting about) can be due to infection (bacterial, fungal or parasites). Consider a broad spectrum antibiotic or an "all in one" product to treat multiple infections. Look in the Aquarium section of the local Petco for options. Follow label directions carefully and remove the carbon filter insert during treatment if indicated.

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