My platy fish has white poop, is thin, and fins are off. What now?

Thanks for reaching out about Fish. Test and correct water quality for pH, ammonia, nitrites and nitrates. If all fish are affected, water quality problems the most likely. Alteration can lead to increased mucous production from the skin (white stuff), but fungal dermatitis or parasites are also possible. A veterinary visit is recommended if the water quality if appropriate, to assess and provide a diagnostic/treatment plan. Good luck.

He may have internal parasites. maintain pristine water quality and confirm stable water chemistry. This can be done by 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. Perform a partial water change, no more than 30% total volume at a time, if indicated. use only conditioned water that is temperature matched to prevent further stress or shock. Check the water temperature as well, since low temps can affect activity, appetite and digestion in fish. Anywhere between 72 F and 80 F is acceptable. Keeping it at the higher end may aid in digestion and defecation. Consider a broad spectrum parasite medication. You can find one in the Aquarium section at the local Petco. Follow label directions carefully and remove the carbon filter insert during treatment if indicated.

Parasites, constipation, stress or bacterial infection are all possibilities. Maintain adequate water quality. Continue with the salt treatment, it can decrease stress, aid healing and may treat minor infection. Consider a product such as PraziPro or General Cure by API to treat for parasites. Constipation can be managed with a 3 day fast followed by feeding bits of cooked, shelled green peas until defecation is normal and regular.

If the tank was not properly cycled before she went in, the water qualityu may be affecting her. Check the water parameters first. Temperature should range bewteen 68 F and 78.8 F (20C to 26C). Using a home test kit, ammonia and nitrites should read 0 ppm. Nitrates should be 40 ppm or less. Platys do best in a pH of 7 to 8.3. Adjust parameters as needed and see if it makes a difference in her behavior. Offer a variety of appropriate pelleted and flaked food as well as freeze dried to see if she has a preference. Platys are livebearers with a gestation of around 28 days. She will become noticeably bigger as her date approaches. If she is pregenant and has fry, you will need to separate her or give the fry plenty of cover in the tank. If not, she will eat them. The stress of a new tank and water may also be a factor. Hopefully, with some adjustments and different foods, she will perk up.

Perform a partial water changes, 30-50%, using conditioned water. Dissolve 1 teaspoon up to 1 tablespoon of Epsom salt per gallon of water in a cup or two of tank water and gently pour it into the tank. This will work as laxative. Fast the fish for 3 days, then start feeding bits of cooked and shelled green peas until defecation and appearance are normal. You can also add metronidazole at 200mg/20 gal to the tank. Repeat the water change, salt and metronidazole every 3 days for 3 cycles. Be sure to treat only the amount of water being replaced with salt and not the entire tank volume. Remove the carbon filter insert during treatment as well.

It doesn't look like Ich in the images provided. Ich will appear as multiple white dots the size of salt grains on the fish. The fish will "flash" or dart about the tank and rub on objects due to itching. The fish may have an infection or the loss of scales may be due to trauma from other fish. Consider separating the affected fish into a separate tank to recover. If this is not possible, maintain pristine water quality in the main tank and consider a broad spectrum antibiotic. You can find one in the aquarium section of the local Petco. Follow label directions carefully and remove the carbon filter insert during treatment if indicated. You are likely at the maximum number of fish in the tank. As they grow, they shouldn't get bigger than 2 - 2.5 inches, and reach adulthood you may need a larger tank or you may need to separate them.

Sorry for the problems. Intestinal parasitism can affect small fish. Please check water quality to ensure ammonia, pH, nitrates and nitrites are appropriate. Taking a fish to a veterinarian for identification of the parasite can lead to a treatment plan for the adults. Sometimes invertebrates (snails) are intermediate host for the parasites, and removing them can reduce the problem. Good luck.