Why is my fish agitated and swimming frantically after a water change?

When performing water changes it is recommended to change about 15-25 %of the water. His helps keep some of the good bacteria in the water as well as decreases dramatic temperature changes which can cause significant stress on the body. I suspect that it is the temp change that is hard in him, however if a dechlorinator was not used in the water then that could be problematic as well. If you feel that is the case please Add a dechlorinator. I hope he improves!

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

Thanks for reaching out about your fish. First, check the water quality for pH, ammonia, nitrites and nitrates. Correct any problems. The water appears fairly green but that in itself does not equate with poor water quality. If the area has high human traffic, that could scare them also. Since the fish school, one scared and there all move. Maybe a visual barrier could provide some security, taller fake plants in the front of the aquarium. Good luck.

Hi there, when you change a tank over you should take some water from the previous tank then make it up with freshwater. You should let this stabilise for one week before adding the fish. If you put a fish straight into a new tank without letting the water acclimitise it can be a shock to it's system. At this point all you can really do is let the fish settle in and don't disturb its tank for a week or so.

Thanks for reaching out about Goldie. There are two concerns here: (1) not apparently eating and (2) high ammonia. For the appetite, try to note if there is feces. If feces, then eating. If appear getting thinner, then not eating enough. For the second problem, this is probably new tank syndrome, and not allowing the biological filter to establish. Water changes are needed to bring down the ammonia as that is toxic to the fish and damaging to the gills. Probably the reason for the frantic swimming. Good luck.

Water quality can definitely contribute to swim bladder disease. Keep the water temperature between 78 F and 80 F. Use a small filter if you can to maintain water quality. When performing water changes, use aged or conditioned water that is temperature matched to prevent stress or shock. Keep a large container of water out for 24-48 hours prior to use. This "aged" water can then be conditioned with StressCoat, NovAqua or similar conditioner prior to changes. Use no more than 1 teaspoon aquarium salt per gallon of water as a general tonic.

Goldfish are surface breathers so seeing them up at the top is not unusual. They are also very dirty fish, so I recommend getting a small pump for aeration and doing a partial water change. There is usually a period of cloudy water after establishing a new fish tank until the bacterial balance is established and stabilized in the tank. I also recommend getting a siphon--type tank cleaner so you can use it to clean the gravel as you remove some of the water. It acts as a vacuum to pull out all the fish poo that settles to the bottom, and the water you remove from the tank is a great thing to water any plants you have with, as it also fertilizes them. Remove no more than half of the tank's water and replace it with clean fresh water that has had the correct amount of water conditioner for the volume you're adding.