If your fish is swimming frantically without going anywhere, crashing at the bottom of his tank, rubbing himself on gravel or rocks, or locking his fins at his side, he may be experiencing significant stress. Talk to your veterinarian about treatment and look into what may be causing the stress and alleviating it.
Your fish may also feel physically crowded in an overstocked tank, which can result in them pacing the glass. Fish need space to swim, and when a tank is crammed with other fish or decorations it can be stressful for them. Unlike in the wild, there is nowhere for them to go if they don't like their current location.
When you observe your fish, check to see if they are bumping into / rubbing up against any ornaments or gravel. If so, this erratic swimming behaviour could be a sign of an external parasite. If you notice anything on their scales, a parasite treatment should be given to them right away.
When dissolved oxygen levels are low, fish hang at the surface and gasp, as the surface area has the highest oxygen level in the tank because it's in contact with the air.
If your goldfish is sitting at the bottom of the tank, then there are a few reasons this can be occurring. It can be health related or related to the environment they are living in. They could also be bottom sitting due to water conditions, parasites or bacteria, stress, or gastrointestinal problems.
Symptoms: You should observe your fish often for any of these signs of stress. Gasping at the Surface: If a fish is gasping his mouth at the surface, this is a sign of stress brought on by poor water conditions, usually a lack of oxygen. Appetite: If a fish is stressed, oftentimes he will not eat.
Increasing water movement is the quickest way to increase oxygen (O2) levels in a fish tank, as it allows more O2 to dissolve and carbon dioxide (CO2) to be released. This can be easily done using an air pump, performing large water changes, manually stirring the water, or placing a fan near the aquarium.
Perform a large water change (as much as 50 percent of the tank's volume). Then increase the water movement by adding a powerhead, airstones, or even an additional filter. These measures will introduce more oxygen to the aquarium, buying some time to address the underlying cause.
“Glass surfing” is when a fish – such as betta fish, gouramis, and cichlids – repeatedly swims up and down along the tank walls. It could be caused by stress, boredom, defense of territory, and other reasons.
If the water temperature is too hot or too cold, the fish could suffer from temperature shock. That can sometimes cause the fish to become extremely lethargic and spend most of their time lying on the tank bottom. Temperature fluctuations can also wreak havoc on some fish species.
A lack of space is one of the main causes of goldfish fighting. If your tank is definitely big enough, try adding or rearranging plants to create hiding places.
Feed 2-3 times daily. It is important to avoid overfeeding goldfish as this can cause indigestion and/or contaminate the tank. In terms of the amount to feed, a good rule of thumb is to only feed an amount that the goldfish can consume in under two minutes or only feed as much as the size of the goldfish's eye.
If your goldfish spends a lot of time just below the water's surface or seems to be gasping at any air bubbles, it may be a sign that your fish is having a difficult time breathing. This might be due to low levels of oxygen in the water, high levels of stress, or something else entirely.
The bubbles introduced into the water by air pumps increase surface agitation, allowing more CO2 to exit and more oxygen to enter the water. Air pumps work best in conjunction with other devices. Biological filters, for example, use bubbles created by the pump to filter contaminants from the water.
But, many fish can survive and recover, given that the hypoxic events are small enough.
Also, just like too little light could confuse your goldfish into thinking it's always night time, too much light will make your goldfish think it's always day. This will throw off your fish's sleeping, eating and behavior just as badly.
Cycling is a process that can be very harsh on fish. It is also possible that the process of performing a water change causes stress to your fish and bacteria or other pathogens that are normally present in the tank take advantage of the fish in its weakened state.
If your fish eats, swims, and usually acts, you have nothing to worry about. However, consider these red flags if your fish doesn't eat their food, is gasping for air, or is rubbing its scales on random objects.
In some cases, mild stress is something your aquarium fish can recover from but, in many cases, it is an early sign of something that can become a major problem. To maintain the health of your aquarium fish, you need to learn how to identify the signs of distress.
Freshwater fish have to invest a lot of energy keeping their internal fluid salt concentration from being diluted by the influx of water across the gills. Increasing salt levels in the aquarium reduces the water influx and releases energy which can be used dealing with stress and fighting disease.