How to treat koi fish with flashing, torn fins, and inactivity?

If you have an activated carbon filter insert, remove it or it will filter out the medication. Confirm adequate water quality and chemistry since both can impact health and healing. Consider adding a broad spectrum antibiotic to treat infection. You can purchase products such as Kanaplex or Maracyn in the aquarium section of the local pet or fish store. Follow label directions carefully. Plain aquarium salt (NOT table or Epsom salt) can be used at 1 teaspoon per gallon of water to reduce stress and aid in recovery.

If you have another tank, it will make treatment easier. It will also preserve beneficial bacterial populations in the main tank since antibiotics may be used. The cornerstone of treatment and recovery is pristine water quality. Keep the water as clean as possible via filtration and regular partial water changes. Use only conditioned water that is temperature matched to prevent stress or shock. You can find a broad spectrum antibiotic in the aquarium section of the local Petco. Follow label directions carefully and remove the carbon filter insert during treatment if indicated. Once the fish has recovered, you can return it to the main tank. If you don't have a "hospital" tank, you can treat the main tank.

This could be bacterial or parasitic infection. It is difficult to determine definitively since the image provided is not clear. Fish can be difficult to photograph. Basic care includes checking water quality and chemistry. This can be done using a home test kit or by submitting a water sample for testing. The local Petco may do this for free or for a small fee. There should be an absence of ammonia and nitrites with nitrates at 20-60 ppm. pH should be as close to 7 as possible, avoiding large swings. Koi can tolerate a wide range in temperature, but generally do best between 65 F and 75 F. Again, avoid large swings in temperature to prevent stress or shock. If necessary, a partial water change can be done to stabilize chemistry and/or improve water quality. If you have other koi, consider placing this one in a hospital tank to make treatment easier and to prevent spread if the condition is infectious. Plain aquarium salt (NOT table or Epsom salt) can be used to reduce stress, improve gill function, treat minor infection and aid in recovery. Dissolve 1 tablespoon per 5 gallons of water in a cup or two of tank water and gently pour it into the tank. Treat for 14 days then reassess the condition. If there is no change, consider a broad spectrum antibiotic or "all in one" treatment. Either can be found in the Aquarium section at Petco. Follow label directions carefully and remove the carbon filter insert during treatment if indicated. All that said, if the spots multiply and appear like tiny grains of salt, it could be an ich infection. In this case the entire tank will require treatment. There are several commercial ich medications that can be used. You will also need to thoroughly vacuum the substrate/gravel in the tank and wipe down all tank furniture.

Fin rot is commonly caused by poor water quality. Submit a water sample for quality testing. Most pet stores will do this for free or a nominal fee. Clinical examination should always include a water quality check, even if you have done so already. Water testing should be performed with a quality test kit, measuring NH4, NO2 and NO3. High ammonia levels, PH imbalances may be responsible for these signs. Oxygen concentration and quality of the filters should be determined as well. If she/he is in a tank larger than 2 gallons move her/him to a smaller tank if possible to make treatment easier. The best treatments for mild fin rot are frequent water changes and aquarium salt. Maintain the water the treatment tank between 76-78'F. Turn the light and filter off for the time being. Aquarium salt can be used at 1 teaspoon per gallon. Dissolve it in tank water before adding it. Perform daily 100% water changes, making a fresh salt solution each day. Treat for a maximum of 10 days.

This could be a bacterial or fungal infection. If there are other fish in the tank, trauma cannot be ruled out. if there are other fish, ideally Tiny should be removed to a quarantine or hospital tank for treatment. If not, you can treat Tiny in the main tank. First, confirm adequate water quality. You can use a home test kit or submit a water sample for testing. The local Petco may offer water testing for free or for a small fee. Aim for an absence (0ppm) of ammonia and nitrites with nitrates at 20ppm or less. perform partial water changes, no more than 30% total volume at a time, using conditioned and temperature matched water. Goldfish are cold water fish that do best between 68 and 74 F. The filter should be rated for at least twice the volume of the tank. Plain aquarium salt (NOT table salt) can be used to reduce stress, treat minor infection and aid in recovery. Dissolve 1 tablespoon of salt per 5 gallons in a cup or two of two of tank water and gently pour it in. Treat for 10-14 days then perform water changes to reduce salinity. Only treat the amount of water being replaced. More often than not, pristine water quality will allow recovery of minor infections or trauma. If necessary, you can use a broad spectrum antibiotic or all in one product, such as LifeGuard (Tetra) or All In One Remedy (Marineland), to treat the tank. You can find these products in the Aquarium section of the local Petco or online. Follow label directions carefully and remove the carbon filter insert during treatment.

Thanks for reaching out about Timothy & Lola. Have you tested the water for pH, ammonia, nitrites and nitrates? Correct any problems. Adding non-iodized salt (aquarium salt) at 1 tablespoon per 10 gallons can reduce osmotic stress but is probably not a treatment for fin rot. If fin/tail erosions progress, antibiotics might be needed, therefore a veterinary visit. Good luck.

Leaving the hospital tank on the floor is fine if that is less stressful for your sick dish. Be sure the top is secured to prevent her from jumping out or other pets from getting in. Survey the area around it for any negative stimuli, such as loud noise, cool drafts or strong vibrations. Make sure the water is sufficiently heated as well. Treat with a combination of a broad spectrum antibiotic and plain aquarium salt (NOT table or Epsom salt). You can find an antibiotic in the aquarium section of the local Petco. Follow label directions carefully and remove the carbon filter insert during treatment if indicated. Dissolve 1 tablespoon of salt per 5 gallons of water in a cup or two of tank water and gently pour it into the tank. Treat for 10-14 days then reassess Leela's condition. Be sure to maintain pristine water quality and keep her as stress free as possible. If you don't want to medicate, you can try a combination of Pimafix, Melafix and StressCoat or similar conditioner. Follow label directions carefully and maintain clean water and a stress free environment.