Goldfish Floating and Sinking Issues

Goldfish Floating and Sinking Issues are mostly caused by improper feeding

Buy the book

Swimming disorders, such as floating haphazardly; bobbing at the surface; uncontrolled swimming, swimming at 45 degree angle or swimming vertical, or swimming upside down; sinking to the bottom 

A more natural environment for goldfish is a shallow pond with plenty of surface area. Aquariums and tanks are typically deeper than wider which can create serious issues for the more sensitive of the fancy goldfish; their bodies aren’t designed for deep and narrow tanks. If we’re going to keep goldfish in aquariums, we must make some compromises. Goldfish are bottom dwellers by nature. On the bottom is where they eat and rest. There’s nothing quite as sad as a goldfish that can’t stay on the bottom comfortably. It may live in constant fear that it will be eaten by a predator whether it’s in a pond or in the safety of an aquarium

The function of the swim bladder is to maintain the goldfish’s buoyancy; giving it the ability to sink or rise, but some experts believe the swim bladder may also act as a conductor for sound or vibration, while some say it’s the lateral line, or central nervous system. Loud booming noises could be one among many reasons a fish loses control of its ability to sink or rise at will

The intestinal tract is connected to the swim bladder by a small tube where gas is exchanged. Ingested food in the tract creates carbon dioxide. This gas is exchanged back and forth from the tract to the bladder giving the fish the ability to sink or rise

Goldfish that are fed too much at one time may gorge, and become constipated. The tract may slow, and even become impacted, trapping gas in the bladder, causing the fish to float aimlessly. If food is withheld for long periods of time, the empty tract will cease to produce gas; causing the fish to lose its ability to rise, and it may struggle to get off the bottom

A goldfish with a sinking disorder caused by lack of food doesn’t have the ability to feed itself because it can’t lift at a 45 degree angle to feed on the bottom or lift to catch falling food in the water. If the bladder is undamaged, it may regenerate and begin functioning again if the fish is fed small and frequent meals daily

Read more about sinking issues

Forcing a goldfish with floating issues to the bottom of a deep tank could cause the swim bladder organ to rupture, causing permanent damage

Goldfish bobbing at surface

Some of the fancy fish develop digestive issues more easily than others, and some fish have floating disorders due to poor breeding or genetics. However true this may be, everything possible should be done to make certain these fish aren’t suffering from constipation, and if this issue is ruled out, the water table should be lowered to assure these fish live comfortably

Good digestive health is critical in eliminating swimming disorders. Feed less more often; feed a variety of veggies and flakes; feed consistently

Goldfish with permanent sinking issues can live a long and healthy life if kept in a healthy environment and hand fed consistently. Goldfish with sinking issues seem to have no preference for deep or shallow water

  • Goldfish has uncontrolled swimming

The deeper your goldfish tank, the more pressure created by the volume of the water. This weight greatly affects some goldfish. The more sensitive goldfish contained in too tall of an aquarium may develop symptoms of uncontrolled swimming, floating or upside down syndrome. Depending on the amount of pressure and for how long the floating goldfish has been affected, or just how weak the organ is, this condition may or may not be life threatening

Never force a fish with floating issues to the bottom or the swim bladder could rupture

Lowering the water table reduces water pressure, eliminating these types of problems in most goldfish that have genetic disorders

Parts of a Goldfish

The swim bladder organ is connected to the intestinal tract where gas is exchanged; giving the fish the ability to sink to the bottom or rise to the top at will

What causes this sensitivity in goldfish may always remain a mystery; in some cases the volume of water itself or perhaps a bacteria infection or digestive disorders could be responsible for weakening the bladder. A loud noise or a direct hit to the tank may be responsible. Some of these goldfish can eat, digest their food, and breathe without any problems, but the majority of these issues are caused from improper feeding. Most goldfish keepers make the mistake of feeding their fish only once, or twice a day; some even less which encourages the fish to gorge

Feed a variety of foods. These fish greatly benefit from eating peas and fresh greens or algae, Mother nature provides a wide variety of vegetation, worms, bugs, fish eggs and fish, and so should we. Never sprinkle flakes or pellets on the surface. Although it’s a trend to feed floating pellets; designed to bring pond fish to the surface for viewing; this trend encourages the fish to swallow air; which may disrupt the gas exchange from the intestinal tract to the swim bladder. All pellets, when fed dry, swell in the tract, causing a slow moving tract or worse

Goldfish are not designed to intake the air that we breathe; instead, they absorb the oxygen from the water as it passes through the gills. The oxygen is then absorbed into the bloodstream

Goldfish Feeding

Digestive Disorders

If you have an air pump or bubbler; remove it and replace it with a water pump. Some fish may intentionally or unintentionally swallow these bubbles; which may create complications with the swim bladder by disrupting the exchange of gas in the tract

  • Goldfish floating upside down

Symptoms exhibited may worsen after water changes because of sudden and large pressure changes. To avoid further injury to these fish, increase number of water changes and decrease amount of water exchanged; performing smaller, but more frequent water changes. The most serious conditions may require the water table be lowered to match the length of the fish from head to tail. Some fish will recover quickly after the depth is lowered, and some will never recover, but the symptoms may be greatly reduced in shallow water. You may not need a pond pump at all if the water is less then 6″ with a fan set up, and daily water changes performed

The fish in the photo below is constipated, and Co2 is trapped in the swim bladder organ. It’s trapped, upside down at the surface

The fish in the photo below is trapped on the bottom, unable to lift due to a sinking issue

Algae, the living plant

No specific type of goldfish is immune to floating issues

The digestive system of the goldfish evolved according to the food supply in its original and natural environment. In the wild, vegetation is found in abundance. Foods higher in protein such as fish eggs, worms, or small fry are scarce, and the competition is fierce. The goldfish spends every waking moment in search of food; finding a nibble here or a gobble there, they ingest small amounts of food frequently. Feed your fish several small meals every day, and feed consistently

Goldfish have no stomachs like most animals

Goldfish floating and sinking issues

Most fish suffering from floating disorders prefer water that is quiet so they’ll have less trouble navigating. The more shallow the water, the higher the oxygen levels. The greater the surface area compared to the body of water, the greater the oxygen levels. Combining the two makes for heavily oxygenated water with or without a pond pump, but only with the use of a fan

To make certain your fish tank or pond is free of harmful bacteria use Oop Boost and  feed the gel food with natural antibiotic if you suspect your fish is infected internally

To determine which issue is causing your fish’s floating disorder by process of elimination.

To relieve constipation use our Float Remedy

If you believe your fish has bad bacteria in its intestinal tract; long stringy pooh; pooh that is darker or lighter in color than the food it eats it may have infection

  • Goldfish swimming upside down

Some of the more delicate fancy fish may experience floating issues in deeper water just because they are awkward swimmers. Most goldfish with healthy bladders can easily tolerate 10 to 12″ in depth

Point a fan where it skims across the surface keeping it exposed to fresh air when the water table is lowered


You may find that when the water table in your aquarium is reduced to a comfortable level for your goldfish, that it may not have enough space. If a larger tank or aquarium is needed, make sure you fill the new tank at the same level as the old to avoid further complications. Increase water changes if this places the stocking level over the standard of 2.5 gallons of water per inch of goldfish body

Some fish preferred an increased depth because of suffering nitrate shock or poisoning in the past. These fish may have to separated from fish that require shallow depth

If you’ve lowered the water table for your floating fish, keep a careful watch over nitrates, as fish suffering from nitrate poisoning need deep water; a lethal combination, floating and nitrate issues

Goldfish floating and sinking issues

The fish in this video has a serious floating issue due to constipation; bad bacteria and possibly due to gulping air from the bubblers or the surface. The red gills indicate the fish was in water with low oxygen levels

Once the goldfish’s condition is stabilized, after a period of time, you may be able to increase the level, but gradually. Try adding one only one inch with every weekly water change. Some of these fish may never be able to tolerate a high water table

Goldfish Behavior


All rights
Author: Brenda Rand