Why is my pleco's skin white and belly bloated after tank cleaning?

Thanks for reaching out. The most important thing you can do is maintain optimal water quality, and this means getting a test kit and testing frequently. Diet is important, and all fish have a dietary requirement for vitamin C. Vitamin C is not stable in fish food for more that a few months, so write the date of purchase on the can of food, and discard after 3 months. It is also recommended to alternate brands of food, as they are all slightly different. Since they have an exoskeleton, the only easy way to measure body score is around the belly. If concave, too thin. Determining illness is tough, so visualizing eating and activity, and comparing it to the past. Good luck.

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.

Add some protein to his diet. This can be in the form of live, frozen or freeze dried blood worms or blackworms. You can also use your preferred search engine to look for "earthworm sticks" to feed him. Check the water quality as well (hardness, pH, etc.). Make adjustments as needed. Low water temps may cause stress and illness. Check your tank heater and temperature.

Hi, and thanks for your question. Begin by submitting 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 water quality is good and there are no major imbalances, your fish should get examined to look for any sign of bacterial/fungal infection and eventually water should be treated. 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.

Thanks for reaching out about your aquarium and including photos. Did you test your water quality prior to the water change? Continue to test for pH, ammonia, nitrites and nitrates. Pristine water quality is needed for health. Are any of the fish new, that could have introduced parasites? Itching/flashing can be due to water quality, external parasites, bacterial or viral infections and other causes. The white lesions on the photo could be fungal infections. A skin scrape and examination under the microscope (at a veterinarian's office) is needed for an attempt to determine a cause. Fungal infections are often secondary problems, so check water quality first. Good luck.

Check the water temperature. This species does best between 68 F and 77 F. Low temps can affect appetite in fish. He may be near the heater for warmth. Check the water chemistry as well. Use a home test kit or submit a water sample for testing. Most pet stores will do this for free or for a small fee. Aim for 0 ppm ammonia and nitrites with a nitrate level of 20 ppm or less. Partial water changes can be done to stabilize chemistry if indicated. Use only aged or conditioned water that is temperature matched to prevent further stress or shock. If it is a "new" tank, there may not be enough food/algae on the bottom for it. Use sinking pellets or toss in some vegetables or greens. Be sure to remove any uneaten food after 24 hours to prevent it from fouling the water.

Thanks for reaching out about your fish. Most of the water additives don't get absorbed systemically since fresh water fish do not drink water. A veterinary visit with a fecal sample is recommended to identify possible parasites and then prescribe a treatment. Most likely the medications needs to be top-coated on food and then eaten. Dosage depends on number of fish and estimated biomass (cumulative weight of fish). Good luck.