Salt is a normal component of many fish systems. Saltwater and brackish systems require salt on a continual basis. But what about freshwater systems? Some internet pages recommend keeping salt in koi/goldfish ponds/tanks at all times. Others say don’t bother. What are the effects of salt on an all-freshwater species?
In a freshwater environment, a fish’s body is more dense than the surrounding water. As a result, water is constantly trying to enter the fish’s body and achieve osmotic homeostasis. A fish’s gills, kidneys and urinary systems are responsible for removing the excess water. When these mechanisms are compromised, the clinical manifestation of “dropsy” can occur. By adding salt to the water, you are changing the osmolality of the environment surrounding the fish, thereby decreasing the amount of water diffusing into the fish. Some people figure this is less stressful for a fish, but after millions of years of evolution, it really isn’t necessary. A fish’s body can handle the metabolic demands of freshwater. It’s the human equivalent to drinking less water so your kidneys don’t have to work as hard.
Most salt-avid fish keepers will keep their fish in very low salinities: 1-1.5%. This level can be very hard to test accurately for and will often vary between 0-3%. This level will not hurt your fish. If you feel like you NEED to have salt in there, that’s fine, but you should not strive for levels greater than 2%.You do NOT HAVE to add salt to your freshwater fish system. Always add non-iodonized salt (not table salt)!
For some parasites, depending on the species and water temperature, higher therapeutic levels of salt can be used to treat the infestation. Salt works by first increasing, then depleting the mucus coat, which many parasites use as a food source and for protection. Once the mucus coat is gone, the single-celled parasites rupture from the changing osmotic gradient. But if you are slowly bringing your salt levels up without realizing it, some parasites have been found to become resistant to therapeutic salt levels, requiring treatment at even higher doses. The higher the salt dose, the harsher the treatment for the fish.
All in all, a little salt is fine, but don’t obsess over it. Your fish will do just fine without it. The only time we recommend salt is for recovery from trauma or surgery. Don’t forget that salt can kill aquatic plants!
We’ve already established that fish get sick, so how can you recognize when something is wrong? Signs of illness can be broken down into two categories: physical and behavioral.
These indicators of illness can be very easy to spot. Physical signs of disease include:
Changes in coloration
Asymmetrical body shape
Etc, etc etc
Most of the times, these changes are fairly obvious, but especially in the case of coelomic tumors, subtle changes can be very hard to spot. Here are some examples of physical signs of disease:
Behavioral signs of disease are harder to spot. If you don’t check your fish out every day, these signs can be very difficult to spot. A 5-minute fish viewing session twice a day is recommended at bare minimum. Behavioral signs of disease include:
Incorrect body position
Avoiding areas of tank/pond
Non-seasonal change in appetite/feeding behavior
In order to recognize “normal” behavior, you may need to look outside your home pond/tank. What may be “normal” in your pond may be very obviously not normal if you watch other fish of the same species in a different environment. Call up the neighbors and arrange a pond/tank social hour at a different home each week/month!
If you have a behavior that you cannot identify as normal or abnormal, CALL A PROFESSIONAL. Our office number is (831) 278-1081. It is better to be certain than let a unknown behavior slide for too long.
For more information on spotting sick fish, including some behavioral indicators, watch our webinar:
Read along with us as we share our exceptional surgery cases!
Lemon is a ranchu goldfish who was adopted with a slight oral deformity. Once day, when going after a large pellet, one side of her mouth luxated and obstructed her oral cavity. Dr. Sanders was able to correct the injury with a few well-placed sutures and Lemon was able to recover. Read more about her story here.
We don’t know why he did it, but Rocky, a shovelnose catfish, decided that the rocks at the bottom of his tank looked particularly tasty. He ended up eating almost a pound of them and they got stuck in his stomach. Dr. Sanders performed surgery to open the stomach and remove the rocks. Read more about Rocky here.
Our buddy Sparky presented with a HUGE tumor on his eye. Rather than trying to cut the tumor away from the delicate cornea, Dr. Sanders elected to remove the eye. Sparky healed up great and you can never even tell an eye was there to begin with. Read his full story here.
How do fish veterinarians decide when it’s time for a fish to go under the knife? Surgery can be very beneficial for fish when it is warranted.
Water Quality Testing
Prior to any surgery, a veterinarian MUST test the water quality. If the water quality is off in any way, recovery after surgery will be hindered. Corrections to water quality must be made prior to any procedure.
In dealing with structures including and next to bones and the swim bladder, radiographs, commonly called “x-rays,” provide great diagnostic info. These are very handy to see if there is any air where it shouldn’t be and if any structures are not in the correct place. For soft tissue, we need…
This tool is one of the most beneficial to evaluate internal structures in fish. For koi, it is how we are able to see gonadal sarcomas and how extensive they are. A small tumor is much easier to operate on that a large one.
Unlike many other pet species, bloodwork is not very useful in many species of pet fish. Reference ranges have been established, but some are too wide, and vary based on water quality and genetics. For surgical procedures, a PCV (packed cell volume) is helpful to understand how much blood a fish loses during a procedure.
Other than constipated goldfish, “swim bladder disease” is a very common home diagnosis. Or the more common vernacular, “My fish has swim bladder.”
Well, all fish have swim bladders, so that fact is correct, but it is not a disease. “Swim bladder disease” is most common in goldfish and koi, with a high percentage in fancy varieties of goldfish. For 99% of koi, swim bladder disease is caused by poor water quality. I have had one case of actual swim bladder disease in ONE case, shown below.
For this koi, her swim bladder is full of an sterile, non-cellular fluid. We don’t know why this happened, but it causes her to scoot around on her belly. But this is our ONE case of an actual swim bladder issue in a koi. We have had two instances of koi with tertiary swim bladders, but not causing any clinical signs.
For goldfish, 90% of our “swim bladder” cases are lethargy secondary to poor water quality. Most of our actual swim bladder cases are fancy goldfish with most likely structural deficiencies. We’ve illustrated this point previously with our case on red moor, Huxley. Compare this comet x-ray below…
To these fancy goldfish…
Goldfish are supposed to have a two chambered swim bladder, but due to their anatomy, these fancy varieties have limited space in their coelomic cavities. This sets them up for buoyancy issues from birth.
Goldfish and koi are also physostomous fish, meaning that they inflate their swim bladders by having a pneumatic duct between their esophagus and swim bladder. When they eat at the surface, it encourages air to enter the swim bladder. This is the main reason we see swim bladder issues. Goldfish are voracious eaters and if too much air gets sucked in, they can have positive buoyancy issues.
Fish with negative buoyancy may not have enough room in their body to support a larger swim bladder. However, being negatively buoyant is much safer than positively buoyant. Fish stuck at the surface are prone to air ulcerations where the skin starts to break down by being exposed to long periods of air.
External floats, such as those praised on YouTube, must be designed with the fish’s external surface in mind. Anything that rubs up against the skin will disrupt the protective mucus coat and cause secondary infection. Any float attachment will be TEMPORARY. We only apply them to get fish the surface to naturally inflate their swim bladder. We can take air out surgically, but we cannot add it in case the swim bladder ruptures.
If your fish is showing signs of negative or positive buoyancy, CHECK YOUR WATER QUALITY FIRST. Only 10% of our goldfish cases are primarily caused by the swim bladder. The other 90% are water quality, diet, maintenance or bullying/trauma. Do NOT add a float without proper surgical prep in order to minimize infection.
To prevent the buildup of dangerous anaerobic bacteria, stir your substrate weekly. If the rocks are larger, use a pond vacuum to suck the muck out from the bottom. To make the job easier, start to scoop out the rocks.
If you have a concrete bottom or liner:
Gently sweep any debris and algae towards your bottom drain a few times a week. If you do not have a bottom drain, use a pond vacuum to suck up all the debris after it settles post-sweep. Be careful with liners not to scrub too vigorously or else you may rip a hole!
If you don’t ever clean the bottom of your pond:
Time to start! If you think there is more than a few inches of mud at the bottom of your pond, get your fish out of the pond and in a temporary holding tub just in case you have pockets of hydrogen sulfide. Dig down until you hit the liner or concrete bottom. Try to keep up with cleaning on a weekly or at least monthly basis to keep it from being such a chore!
If you do not have a bottom drain:
Never fear! Even if you didn’t add a bottom drain when you put in the pond, one can be retrofitted. Bottom drains make cleaning ponds so much easier! Contact your local pond professional to get one added to your pond today!
A common problem we see, especially in betta fish, is known as Fish Bowl Syndrome. Essentially, it can be broken down into one main issue:
Your fish is in a bowl.
Problem #1: Your fish has no filtration for processing of dangerous ammonia waste. Without a place for bacteria to grow and filter the water, your nitrogen cycle can never be established. Some may argue that betta fish get pushed around by filters, but if you chose the right one and slow the flow, it is perfectly suited to bettas.
Problem #2: You fish has no oxygen circulation. Fish tank filters are great at adding in oxygen, even in slow-flow mode. In a stagnant bowl, your fish is limited to what air diffuses from the surface. Yes, betta fish have a specialized labyrinth organ used to squeeze oxygen from the air. This is a short-term adaptation mechanism used to survive in drought conditions. It is NOT a long-term survival technique.
Problem #3: Your fish has no temperature stability. We’ll pick on betta fish again. Bettas are tropical and need heat. The small volume of a bowl causes temperatures to fluctuate dramatically. Watch the difference in ambient room temperatures on a 1-gallon fish bowl and a 10-gallon fish tank. It’s the same as you stepping out into freezing temperatures wearing a t-shirt or a coat.
Problem #4: When doing bowl water changes, most often, you will take your fish out of the bowl and put them in a tiny container while you empty all the water out of the bowl and scrub it clean. Since you have no filtration or oxygenation, you can swing the water chemistry parameters, including pH and temperature, very rapidly, causing your fish to stress and possibly die.
Fish bowls are ancient technology invented before there was electricity. With all the modern updates to fish-keeping, isn’t it time to let the fish bowls go? Unless, perhaps, you use them for this purpose:
There are many ways to build a koi pond, and some methods can affect your maintenance regimen. Your pond bottom, also known as your substrate, can dramatically change how much time and effort you spend cleaning your pond. We’ll cover some of the most common bottom covers and the pros and cons of each
Pros: This substrate is the most eye appealing of them all. It breaks up the industrial look of a synthetic fish environment and can provide hold for and uncontained plants.
Cons: You will need to stir the gravel/small rocks frequently to keep them from cementing together. A pond vacuum will be of little use and will keep collecting all these small stones. This substrate collects lots of debris and is hard to clean. If the substrate is deeper than 3″, you run the risk of anaerobic bacteria production once they are cut off from the oxygen in the water. This can create pockets of hydrogen sulfide that can kill fish if mixed into the water supply.
Pros: Another aesthetically appealing bottom substrate. Larger rocks are more suitable to a “river” appearance.
Cons: Your pond vacuum will work slightly better if the substrate is too large to fit up the hose. If the stones are too heavy, you will have a very hard time cleaning between them. Multiple layers of stones will be more likely to collect debris than only one layer of rocks. This layering effect can contribute to cementing of rocks together and formation of hydrogen sulfide producing anaerobic bacteria.
Pros: A liner bottom is one of the easiest substrates to keep clean. They work well with a bottom drain.
Cons: Pay special attention to the thickness of your liner. Thinner liners may be more economical, but they will not last as long as thicker liners. They are prone to tears from rocks, root growth and boots. They are not as aesthetically pleasing and deep folds can potentially trap fish.
Pros: Concrete bottoms with a spray-applied liner are very easy to keep clean. They are more durable than simple liner ponds. Leaks from tears are not an issue as this type of bottom stands up well to abuse from rocks and boots.
Cons: This is one of the most expensive substrate options for fish ponds. If your concrete is not mixed properly, you will lose chunks of your bottom, leading to leaks. They are susceptible to earthquake damage if this is an environmental concern. Be sure both your concrete mix and spray liner are appropriate for usage with fish. You cannot change the shape of your pond or add any underwater features later with this substrate.
Cons: Your lack of cleaning effort creates a dangerous health hazard to your fish. Dense planting and layers of debris and fish waste create layers of bacteria that lose contact with oxygen in the water. These anaerobic bacteria use sulfur as a food source. If you mess around in the muck or your fish try to flash on this surface, you will release hydrogen sulfide and kill all your fish.
It is impossible to recreate a native environment in a synthetic fish system. “All natural” systems in wild environments use multiple species working together to balance waste management. In a man-made pond, you are missing many of these critical elements. Do your regular maintenance!
Just like your cats and dogs, your pet fish can benefit from a yearly wellness exam. By bringing your vet in before you notice any issues, health problems can be caught earlier and treated more effectively. The spring months are the most common times of year when problems with koi occur. Save yourself the stress of trying to guess your koi issues and get it straight from the best trained source in California & Nevada.
Our Spring Pond Package for 2019 will have some new benefits for all pond owners. To schedule, call (831) 728-7000.
Tumor Screenings for Female Koi
With the increased incidence of gonadal sarcomas, we usually do not catch them in time, given their sneaky, lack-of-external, appearance. By implementing regular screening, we can find these tumors much earlier and fish can undergo life-saving surgery.
Recommended Products for Koi Owners
With the closing of our store, the Fish Vet Store, we want to be able to provide our clients with all our best product recommendations. All Spring Pond Package clients will receive a 20oz bag of UltraBalance Maintenance koi food, an API Freshwater Master Test Kit + kH test kit, an infrared thermometer and a signed copy of Dr. Sanders’ book, Healthy Koi Made Easy.
Water Quality Screening
Fish health is directly linked to water quality. Our spring pond checks include full assessment of fish water quality parameters. If there’s an issue, our veterinarian will make recommendations to correct them quickly and easily.
Call (831) 728-7000 to schedule your Spring Pond Checkup today.