Sinking SBD: How to stay up when your betta gets down

A look into the causes behind sinking SBD and possible fixes for the condition.

Firstly, WOW! So may new followers! Hello everyone! Let’s learn more about betta health!

Of the two different types of Swim Bladder Disorder (SBD), sinking fish are far more preferable than their cousins the floating ones. But why is that? Let’s take a look into what sinking SBD actually is first.

Bettas with sinking SBD can behave in different ways. More mild cases might drag their back ends, dogsit, or get floppy while resting. More severe cases with no natural buoyancy might become heavy and sink to the bottom of the tank, unable to swim normally.

This condition is characterized by an imbalance of the swim bladder itself. The gas-filled organ is vital to maintaining natural buoyancy within the water column and when something interrupts the natural function of the swim bladder, SBD occurs.

There are two and a half causes for sinking SBD. The first one is that the swim bladder becomes deflated and loses it’s gas. Much like a popped balloon, bettas with collapsed swim bladders cannot float as they normally would. This can happen due to injury but is more commonly seen as a slow progression of onset SBD as the bladder deflates. Genetics almost certainly play a role. The second cause for sinking SBD is that the swim bladder, while normally filled with gas, becomes filled with fluid instead. This can happen due to cysts, masses, cancers, and other internal factors. The last cause comes from sinking SBD that originates from outside of the swim bladder. Natural buoyancy can become off-balance from a variety of factors such as overindulging in frozen foods— an easy fix— to large fluid cysts present in other areas of the body that weight the betta down so much that the swim bladder cannot compensate for the difference. Spinal deformities can also cause sinking SBD symptoms. All three of these causes can make your betta display behaviors that are consistent with a sinking SBD diagnosis.

To begin making a plan to combat sinking SBD, fish owners must first uncover why their betta is sinking. Now that we’ve gone over the types of underlying causes, it’s up to the owners to discover which one is the one causing the symptoms. With the last one, visually knowing that your betta overate or has tumors or such is the easiest way of deciding the cause. But figuring out if your betta’s swim bladder is collapsed or fluid-filled can be harder to know.

Here’s how I do it:

First, you’ll want to cup your betta in a clear container, turn out the lights, and then shine a strong, bright flashlight through the opposite side of them. This should illuminate the internal structures of the betta to the naked eye. The swim bladder in a healthy fish should be obvious as a long, clear organ that starts behind the gut and continues down the tail, hugging the spine the whole way down. If there is no evidence of a swim bladder at all when viewed like this— it has deflated. If you can still make out the swim bladder but the shape is warped and it appears darker than it should be— it’s fluid-filled. This light trick is also a great way for picking out internal cysts and other growths as well, and it can be more difficult to distinguish body parts on dark-scaled fish. Some lighter fish or cellophanes have swim bladders that can easily be seen without a light.

Now let’s talk about what to do next. If your betta’s swim bladder appears fluid-filled, you have a few different options for treatment. Some people swear by Epsom salt baths, similar to dropsy treatment, but I personally have not experienced any results with this method. Some fish keepers look into draining out the fluid, but it always returns and to me the risk of introducing infection plus the stress of the procedure makes this route undesirable. For me, the most important thing to do for these SBD cases is focus on symptom management. Sinking SBD is not a death sentence. Bettas with this condition can live fully fulfilled, healthy lives with a little extra love and care.

If your betta is sinking from a collapsed swim bladder, you have a few more options aside from symptom management. This condition has long been thought to be chronic and uncurable. For a very long time, it was thought that all forms of organ-based SBD were permanent.

But I figured it out.

For collapsed swim bladders, I fill a small container with no more than 3 inches of water. All available swimming space is crammed full of soft, fluffy moss to restrict betta movement. The moss will also prevent any sores from forming on areas of the body that the betta might constantly rest on. Once in this temporary setup, you can feed and clean the tank as normal but it is important that the betta remain as still as possible. Let them stay like this for 4 weeks, then raise the water level and see how they do. If they’re still sinking, confirm that the swim bladder is still collapsed and try again.

With this method, I’ve seen 3/4ths of sinking bettas regain swim bladder function and recover their natural buoyancy. But I will not lie to you— this is an extremely rough treatment plan. It’s hard to keep a betta still for so long. It’s rough on them. But I imagine these cases much like one would a broken bone. To heal a swim bladder, you need a constant, maintained water pressure and total stillness. Bones are immobilized while healing. Swim bladders must be treated the same way.

In reality this is difficult to do, but if successful I have seen incredibly miraculous recoveries. For a condition long-thought chronic, this new method is showing promising results.

Also, no pictures this time due to Substack’s post limit feature. Any time I tried to add a photo the site got mad at me. It’s hard to try and condense 8 years’ worth of knowledge into such short posts. Maybe I should just post more? Or do a photo album to go with this post to explain what I’m talking about? Thoughts?