Something Is Not Quite Right With Your Goldfish: How To Stop Goldfish Problems Before They Become All-Out Diseases

by Adam Till

A Note Of Warning About Goldfish Disease and The World "Wild" Web

First off, I'm very sorry that you're having trouble with your goldfish.

There is an awful lot of conflicting information on the web, and most if it is because of websites repeating information from other websites without having direct experience with treating disease themselves. Usually this is best recognized by the lack of original photographs of the disease processes, and a lack of references to claims made in the article or treatments suggested.

Please be careful treating your fish using such information, and always contact an aquatic veterinarian for assistance whenever possible.

Since I am just a breeder and not a vet I cannot legally diagnose or prescribe a course of treatment for your fish, so instead I will simply offer a description of what I do when I encounter these issues.

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Have you ever wondered in frustration how much easier it would be to take care of animals, and fish in particular, if they could just talk to you?

It turns out that they do...sort of.

Instead of using words to communicate or whining like an unhappy dog, however, fish "talk" to you through changes in their behavior.

Learning To Trust Your Gut Around Goldfish

If you're anything like I am, you might be tempted to try to "learn" everything you can on a subject that you're interested in.

Though that can be great when you're starting out, at a certain point you just have to learn to listen to your gut a bit.

If you're walking by your tank, or feeding your fish, pay attention to any little tingly feeling you might get that says something isn't quite right.

If you're in a rush, or worried that you might miss something important, you can even whip out your phone and take a quick couple of minutes worth of video of the fish that are giving you the case of the tingly's.

This sort of thing is very important to build up as you become a more experienced goldfish keeper, and you'll find you can actually take steps to become more "tuned in" to these sorts of feelings.

Building A "Smart" Gut

When you get a funny feeling about how your goldfish is behaving, what's actually happening is that you're subconsciously noticing patterns that don't quite fit the norm.

Just Soak In Some Tank Time

One of the biggest differences between beginner keepers and ones that are more experienced is just that...experience.

As a result, one of the best things you can do is to set aside 15 minutes a day to enjoy your tanks and fish.

Although closely observing each fish with a careful, focused eye has its place, take at least some time to use what in the horse world we'd call "soft eyes".

Soft eyes mean to just take in the big picture without focusing your stare at any one object. Not only will doing so allow you to relax a little more (and probably cause less stress in your fish from a potential "stare down"), but you'll take in more of the finer details of what's normal and what isn't over time. 

In fact, given the work involved in keeping fish, it's important not only to the fish's future health but to your own sanity as well. One of the points to use when considering whether to keep or rehome a fish can be whether you choose to take the time to enjoy them everyday, or whether you're just going through the motions to taking care of them on a surface level.

As simple as it seems, having that soak time can actually make you a better aquarist and goldfish keeper as well. 

Start to Jot Down Some References

When you start to get that funny feeling that something isn't right in goldfish land, you're often responding to what you're seeing the fish doing.

That said, while the majority of what you'll later remember will be how the fish is acting to your eyes (humans are primarily visual creatures), what your subconcious mind is actually responding to will also encompass things like weather patterns, pressure, temperature, and the environment around your tank.

This sort of information would overwhelm you if you had to process it on a conscious level all the time, so your brain neatly organizes it into little patterns of "normal", and only brings it to your attention if something seems out of whack.

As a result, when you notice something funny, consider taking a little notebook and making note of things like weather patterns, feeding changes, or how you're feeling yourself that day (having a headache might be a hint that the air pressure is changing, for example).

If you have those notes to look back on if something starts to repeat itself, you'll be better armed with information to help you make decisions later on.

Good goldfish breeders do this all the time, and honestly the more you record without making it a chore, the better.

Look Deeper Than The Surface

How many times have you heard people say something like "my fish got sick without warning", or even something like "feeding bloodworms caused my fish to get sick".

Although the above statements have the potential to be completely true, they're also very likely to be a result of people attributing the last thing they did or noticed to the problem they're encountering.

As another quirk of human behavior, all of us can get into weird, superstitious habits if we don't take a second to think things through.

Yes, it's possible for a fish to get sick "all of a sudden", but more likely it's a serious of small, repeated stresses and changes that ultimately cause them to get worn down.

So while it's not the end of the world to do things like bump a maintenance day to suit a holiday once in a blue moon, or to keep the cheaper jumbo bag of fish food by the tank rather than a smaller one in the refrigerator where it won't spoil, adding up too many of these sorts of things can be the chain that results in the fish that "suddenly" gets sick.

Have Some "Just In Case" Goldfish Supplies

Although as you can see your best tools to evaluate the health of your goldfish don't cost a cent to own, some very inexpensive household supplies can also come in handy with "not quite right" fish.

The first product that can seem like a "miracle cure" at times (though it obviously isn't) is plain old drug-store type 3% hydrogen peroxide.

I use this quite frequently both in a bath form, and directly applied to minor wounds and superficial fungal infections or wen infections (please learn the difference between normal wen growth and an actual infection, however).

As a bath, the normal dosage I use is 2mL of the solution dissolved in each gallon of water that the goldfish is held in. Ideally this is not going to be the main tank, however, since hydrogen peroxide as an oxidizer can affect filter bacteria negatively (if generally temporarily).

As a result, my normal go-to involves:


Gently move your fish (ideally by hand if you're comfortable to avoid damaging their fins and scales) from his main tank into the bucket, and set a timer on your phone or microwave for 2 hours.

After two hours, place the fish back in his main tank, empty the bucket and give it a quick wipe down with vinegar.

It's amazing how often a "not quite right" fish responds well to this sort of treatment, and it's even had significant benefits with some serious illnesses at times.

Swabs are also very useful at times, and I'll let Jenny from Solid Gold explain how that procedure is handled:

The second product that I strongly suggest people own at all times is a solid quantity of plain aquarium (sodium) salt.

These smaller containers are great for people with limited storage room or only a couple of tanks, and are easily available online or from most pet stores, but an even better option for people with more tanks is aquarium safe softener salt like Morton's Aquarium Salt.



These bags will last most people a LONG time, though they do take up a fair amount of space to store as well. Please keep in mind that not all softener salt is pure enough for aquarium use, however, so do read your labels closely.

For fish that are experiencing breathing issues (if you notice that their breathing rate is faster than normal), or ones that just don't seem quite themselves, adding 1 tablespoon per 3 gallons of tank water to their main tank (if unplanted) or a hospital tank can really help ease their issues at times.

That said...

Don't Do Things Or Add Products "Just Because"

Sometimes people get in the habit of adding products because the label does a great job of selling, people at stores offer well meaning advice without having any substance behind that advice, or simply out of habit.

All those extra products just make diagnosing issues harder when problems do arise, however. 


Some people have been told by their local fish stores to add aquarium salt to their tanks all the time.

The root of this advice, if they're even aware of it, tends to come from the fact that livebearers like guppies are often raised overseas in brackish (nearly ocean) water conditions, and frequently fall apart if placed in straight fresh water.

This is not an issue with goldfish, and can safely be ignored.

The other argument for adding salt on a regular basis is that it's supposed to have some sort of health, anti-parasite, or anti-fungal benefit depending on who you talk to.

Although salt has an amazing number of incredibly helpful uses, using it in low-grade concentrations all the time just makes it LESS useful when an actual problem arises.

Not only that, but it adds extra load to kidneys, isn't helpful to a lot of aquarium plants, and just adds extra cost and complexity to your water change schedule.

Use it when it's warranted (ie, when you have a problem), but not all the time or you risk actually causing issues.

pH Adjusters

Please don't use these with goldfish.

Yes, I realize that there are a bunch of different websites out there making claims about the ideal pH range for goldfish, and usually advocating for something like "ph 7-7.5" or the like.

This often sends new goldfish owners who live in hard water areas running for the pH Down chemicals, and starting their fish on a roller coaster of pH swings (one of the most harmful things you can do to a fish).

First, please be aware that a LOT of goldfish breeders live with (and LOVE!) hard water in the 8-8.5 or higher range. So do our fish...goldfish love hard water, and baby goldfish thrive with the extra minerals to buffer their waste and build strong bones and tissues.

What the bottle doesn't do a good job of telling people is that if you have water in the higher ranges (8 and above), it will generally laugh at those sorts of chemicals.

You'll add some pH down, run a pH test that looks satisfyingly low, and come back later to note that the pH is back basically where it started from. What happened?

In order to get a pH in the 8's to start with, your water is generally going to be high in what are called carbonates (measured as KH). Those carbonates act to resist changes in pH, and are reacting with the acid in the pH Down chemical to counteract their effects.

Adding enough acid to use up most of the carbonates is not only expensive, but it's actually using up your best defense against pH swings as a result of waste in the tank. Your pH will tend to drop over time as a result of fish respiration and waste production, and if you ever talk to someone who has very soft water, you'll know that they're beginning to add the very carbonates that your chemicals are trying to remove!

Arguments about chemistry aside, the just need to realize that the biggest thing your fish wants is a STABLE environment...not one that's "ideal" according to some random website or book. That's best achieved by leaving your chemistry alone if it's on the high side, or adding a bit of crushed corral to your substrate if it's on the low side (pH less than 7).

Algae "Fixers" and Water Clarifiers

Having no direct experience using these chemicals, I can't technically give any recommendations on their use.

That said, I will say I've helped more than a few people who started having issues around the time that they started using some of the more popular chemicals designed to fight algae or clear up water.

The best fix for algae is a good algae scraper and a light timer, and the best "water clarifier" is a water change and maybe a box filter filled with polyester batting (also available from Walmart crafts) that gets changed each week if you're really a fan of crystal clear water.

If your fish is experiencing issues that started when you decided to do some "chemical maintenance", consider discontinuing their use.

Test Your Water

You knew I was going to get around to saying this, didn't you?

I know that getting people to test their water with a halfway decent set of test strips or liquid tests can be like pulling teeth, but few things are more directly likely to tell you of an impending problem than a water test result that's showing changes from the norm.

Yes, the tank might have been humming along just fine for years, but if you test on a regular basis you might notice that the city has added extra chlorine into the water supply (Tetra test strips have a chlorine bar), or that your fish spawned while you were away and the milt from the males is funking up your nitrite levels.

On a more subtle level you might also notice that, while your filter handled the load of your young fish just fine, it's starting to struggle a bit now that they have some size and you're feeding more.

The ease of testing with strips is most of why I recommend them for this role, and you can still easily back them up with liquid tests if you suspect something might be going on that needs a second opinion.

If you'd like some help reading your water test results, I even have a handy calculator that will tell you exactly what you need to do based off your exact results.

When In Doubt, Change Some Water

Even if you ignore everything written above, one of the simplest ways to help your fish if you have the slightest doubt about their health is to do a water change.

Some wise goldfish keepers once said that the art of keeping goldfish is really more the art of keeping good water, and they're not far wrong.

In fact, if your goldfish are perkier after doing a water change, that can actually be a sign that you should change water more often. Healthy fish in healthy water will barely notice a water change, and the fish will just act like it's their right rather than a treat!

If you suspect you have more going on than meets the eye, please click through to our health area and hopefully I can give you a hand.

Good luck, and happy goldfish keeping!

Adam Till
Adam Till


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