Why do my fish struggle to swim on their side after eating?

It is possible that she has a swim bladder disorder. Many things can cause this, only some of them reversible. Try feeding her peas for the next few days and see if that helps. If it does, then include them in her diet several times a week.

He may be dealing with some swim bladder issues. The swim bladder is what keeps a fish upright and controls buoyancy. Infection, poor water quality or constipation can affect the swim bladder. Perform a water change. Use aged or conditioned water that is temperature matched to prevent further stress or shock. My choice for conditioners are AmQuel and NovAqua. You can purchase them in most pet stores or fish stores. Bettas are warm water fish and do best between 78 F and 80 F. Anything below 75 F will be stressful. A small tank heater may be necessary to maintain proper temperature. Dissolve 1 teaspoon of plain aquarium salt (NOT table salt) per gallon of water in a cup of tank water and gently pour it in. This will act as a general tonic reducing stress, improving gill function and treating minor infection. Change the water daily to maintain quality and dissolve just enough salt to treat the water being replaced. Fast him for 3 days, then offer small bits of cooked, shelled green peas until defecation and swimming are normal. You can soak the bits in some garlic juice to stimulate his appetite and boost the immune system. Transition to a quality pelleted diet and fast for one day each week to maintain GI health.

Check water chemistry first. Use a home test kit or submit a water sample for testing. Aim for an absence (0 ppm) of ammonia and nitrites with nitrates at 20 ppm or less. Perform a partial water change to stabilize water chemistry and/or to improve water quality. Use only conditioned water that is temperature matched to prevent further stress or shock. Bettas do best between 78 F and 80 F. By your description, the issue may be swim bladder disease. This can be caused by infection (bacterial or parasites) or constipation. Maintain water quality as described above. Fast the fish for 3 days then resume feeding bits of cooked and shelled green peas. This will help with constipation. If this doesn't help. you can get a broad spectrum antibiotic from the local pet store. Look in the aquarium section. Follow label directions carefully and remove the carbon filter insert during treatment.

This is a classic sign of swim bladder disorder. Check water quality and chemistry. 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 0 ppm ammonia and nitrites with nitrates at 20 ppm or less. pH should hover around 7 and water temp should range between 65 F and 72F. Perform a partial water change is necessary to stabilize chemistry and improve water quality. Use only conditioned water that is temperature matched to prevent stress or shock. Pristine water quality is the foundation for recovery and healing. Next, fast her for 3 days. Resume feeding bits of cooked, shelled green peas until she is swimming and defecating normally. You can fast her one day a week in the future and offer green peas to maintain regularity. If symptoms persist, consider a broad spectrum dewormer and a broad spectrum antibiotic. You can find both in the aquarium section at Petco. Follow label directions carefully and remove the carbon filter insert during treatment in indicated.

Bump the temperature up to 80 F. The warmer water may aid in digestion. Continue feeding bits of cooked, shelled green peas until he is defecating normally and regularly. If internal parasites are a concern, PraziPro or General Cure (by API) may resolve the issue. PraziPro is safe for the snails. If you decide to use General Cure, it would be safest to remove the snails during treatment.

From your description, I think swim bladder disease is possible. There is a really thorough article that I will link below. When you check water parameters, it is important to make sure you also check nitrites and nitrates. Ideally, ammonia and nitrites should be zero and nitrates should be equal to or less than less than 40. If nitrates are zero, it indicates that your tank is not quite nitrogen cycled. If it is higher than 40, then you need to do at least a 50% water change. https://www.thesprucepets.com/swim-bladder-disorder-in-aquarium-fish-1381230

Usually lack of water quality, lack of oxygen, overcrowding and abnormal temperature are all common causes of this behaviour. They could be hungry as well, but usually they come to the surface at certain time or in response to visual stimuli like your presence. 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.