My goldfish has brown spots and it's getting worse. What to do?

Elevated ammonia levels can result in "burns" which may turn fins and scales black. Use a home test kit or submit a water sample for testing. Most pet or fish stores will do this for free or for a nominal fee. If ammonia levels are elevated, daily partial water changes, using aged or conditioned water, can decrease ammonia to safe levels (0.25 ppm or less). StressCoat or plain aquarium salt (NOT table salt) can aid in healing. Dissolve 1 teaspoon of salt per gallon of water into a cup of tank water and gently pour it into the tank. Confirm adequate filtration. The filter should be rated for at least twice the volume of the tank. You can change 20-30% of the tank water every couple of weeks. Use only aged or conditioned water that is temperature matched to prevent stress or shock.

Check the water chemistry. Two goldfish can quickly overwhelm a tank with their large bio load. Aim for 0.25 ppm (parts per million) or less ammonia, 0 ppm nitrites and 40 ppm or less nitrates with a temp between 65 and 72F. If water chemistry is good, it is possible the red marks are from the pleco. They are notorious for sucking the slime coat off goldfish leaving red marks and wounds. Partial water changes, 30-50%, using aged or conditioned water that is temperature matched are safer and less stressful than complete changes. Give the antibiotics time to work. You can add in plain aquarium salt (NOT table salt) to aid healing. Dissolve one teaspoon per gallon of water in a cup of tank water and gently pour it in the tank. Perform partial water changes after 10-14 days to reduce salt content.

Check the water chemistry. The discoloration could be due to elevated ammonia levels which can cause "burns". 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 20ppm or less. Perform partial water changes to stabilize chemistry and/or to improve water quality. Use only conditioned water that is temperature matched to prevent stress or shock. The Neons (blue fish) appear to be infected with Ich, a parasite. Treatment is possible with commercial products found in the local Petco. Follow label directions carefully. You will need to treat the entire tank until all traces are gone. Removing a lump from your fish on your own is never recommended. You can cause severe injury. Most broad spectrum antibiotics (Kanaplex, Maracyn, Maracyn 2, etc.) found in the aquarium section of the local Petco should help treat or prevent infection. Choose one and follow label directions. Remove the carbon filter insert during treatment if indicated. Maintain pristine water quality via filtration and regular partial water changes to aid in recovery. You can feed frozen worms, just thaw then first in a small cup then place them in the tank.

Although a picture could be extremely helpful to determine the underlying cause more specifically this presentation could be due to a bacterial or a fungal infection usually. I would recommend to make sure water quality is good first of all. Most pet stores will do this for free or a nominal fee. Then, as a general approach, I would recommend to set up quarantine tank: make sure the tank is well oxygenation and has some plants for hiding; - add 1 teaspoon of aquarium salt per gallon; - add this product https://www.liveaquaria.com/product/4410/?pcatid=4410 as indicated; - leave your fish there and feed him regularly for 3-4 days until you don't see any improvement - If no results at all are seen after 4 days a check up would be needed as more specific tests may be needed to establish a specific diagnosis. Hope this answer was helpful, but please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further. Please find the time to give us a feedback about the consultation as that will be used to improve our service.

Black spots or discoloration can be caused by elevated ammonia levels. Test water chemistry using a home test kit or submit a water sample for testing. Most pet or fish stores will do this for free or for a nominal fee. Ammonia and nitrites should be 0.25 ppm (parts per million) or less, nitrates can be 40ppm or less. Partial water chnages daily should be done to decrease ammonia levels. Use only aged or conditioned water that is temperature matched to prevent further stress or shock. Elevated ammonia levels can be caused by overfeeding, new tank syndrome or overstocking.

It could be an infection (bacterial or fungal) or it could be due to trauma from other fish or tank furniture. Confirm proper water quality and chemistry. You can try some plain aquarium salt (NOT table salt or epsom salt) as a general tonic. It may reduce stress, improve gill function, treat minor infection and aid in recovery. 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 the condition. Perform partial water changes to decrease salinity afterwards. Use only aged or conditioned water that is temperature matched to prevent stress or shock. Goldfish are cold water fish and do best between 65 F and 72 F.

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.