Why is my goldfish frantic in 5-gal tank, spitting food, high ammonia?

A 5 gallon tank is insufficient for goldfish. They produce a larger than normal bio-load (wastes) that can quickly overwhelm a small tank. Ideally, one goldfish should be in a 20 gallon tank with an extra 10 gallons added per additional goldfish. The filter should be rated for at least twice the volume of the tank. They are likely succumbing to ammonia and/or nitrite toxicity. If you test the water, it is likely both parameters will be dangerously high. Perform a 50% water change. Use only conditioned water that is temperature matched to prevent further stress or shock. Goldfish are cold water fish and do best between 65 F and 72 F. Plain aquarium salt, NOT table or Epsom salt, can be used to reduce stress, improve gill function and aid in recovery. Dissolve 1 teaspoon per gallon in a cup or two of tank water and gently pour it into the tank. Treat for no more than 14 days then perform a partial water change to decrease salinity. A 5 gallon tank would be appropriate for one male Betta or a small school of Neons (3-5).

There are a few possibilities including normal adjustment or something wrong with the water quality. Also, you will need a bigger tank for Nutty that includes a filtration system. Here is a link about goldfish care: https://www.petcoach.co/article/how-to-help-your-new-goldfish-thrive/ https://www.aqueon.com/information/care-sheets/goldfish Make sure the water quality is good for Nutty. I hope this helps and please feel free to post any additional questions.

Check the water chemistry and quality first. Elevated ammonia or nitrite levels can be toxic. Partial water changes can be done to stabilize and improve water chemistry. Use only aged or conditioned water that is temperature matched to prevent further stress or shock. For goldfish, a range of 65F to 72F is recommended. Check the filter and rinse the sponge with tank water, not tap water, to spare beneficial bacterial populations and to maintain water quality. The tank may not be large enough to support 5 goldfish. Generally, 20 gallons should be allowed for the first goldfish then a 10 additional gallons should be provided for each additional goldfish. This is due to the larger than average bio load (wastes) they produce. Consider a larger tank or decrease the number of fish in one tank. Use a filter that is rated for at least twice the volume of the tank and add an airstone and pump for increased oxygenation. Plain aquarium salt (NOT table salt). Can be used as a general tonic. It will reduce stress, improve gill function, aid in any recovery and may treat or prevent minor infection. Dissolve 1 teaspoon of salt per gallon of water in a cup of tank water and gently pour it into the tank. Treat for 10-14 days. When performing water changes, add salt only to the amount of water being replaced, not the entire tank volume.

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.

Thanks for reaching out about Timothy and Lola. First suggestion is to get a large tank. The general rule of thumb is 1" of fish per 3 gallons of water. Test and correct water quality for pH, ammonia, nitrites and nitrates. The better the filtration, the higher the bio-load. So better filtration or a second filter could help. Good luck.

Check the water chemistry. A large water change can cause ammonia spikes or other imbalances. Check the water temperature as well. Goldfish do best in cooler water, between 65 F and 72 F. Consider a quarantine tank for him if he is the only symptomatic fish. Continue with the medications as directed on the package.

Thanks for reaching out. Sounds like new tank syndrome, which is the time it takes for the biological filter to come up to speed, reducing ammonia to nitrites to nitrates. Continue to test and perform water changes as needed, giving the filter time to establish. Good luck.