Why is my goldfish turning white?

Your goldfish isn’t turning white, it’s just losing its color! There are a few reasons why this can happen but most of them are things that you can easily fix. It is not uncommon and is usually related to a change of environmental parameters. 

Some friends we know have goldfish and asked us why their fish are turning white, they were quite concerned. Their goldfish were more whitefish now and wondered what was going on, was it their fault?

We’ve heard about this time and time again and it’s not uncommon so we asked them a few questions and soon got to the root of the problem.  For anyone else worried about this, then here’s what you need to know if you’re wondering why your goldfish is turning white.

Why is my goldfish turning white? White goldfish

Should You Be Concerned Your Goldfish has Changed Color?

First, and foremost, you’re not alone. It’s easy (and common) to think when something unexpected happens like this that you’re on your own and what you’re experiencing hasn’t happened to anyone else before. Is this your fault? Have you done something that has caused your precious fish to change color? But don’t fret, this is more common than you perhaps think.

Really Interesting Facts About Goldfish (honestly!)

First, let’s look at the facts. Did you know that goldfish are a type of carp? Also, did you know (I should charge for all this information I’m giving) that in the wild goldfish aren’t typically gold but are an olive green color? They have also been bred to be different colors such as yellow, red, black and brown.

Also, did you know that goldfish were first introduced around a thousand years ago in China when the people there started breeding the silver carp? From this point, a mutation occurred and the result was a fish with orange-yellow scales. However, the royal color was yellow and no-one else was allowed to use that color apart from the royal family. Therefore, the population had to just make do with the orange variety, hence the goldfish.

Also, did you know that the goldfish that you have (the specifically bred commercial fish) is only suited for indoor living and if you tried to ‘let them loose’ into the wild, they wouldn’t survive? However, there are breeds of pond goldfish that can survive quite happily of course in outdoor ponds and you’ll find these get quite a bit bigger than the one in your aquarium.

The goldfish is by far the most popular pet fish and are easy to find. They’re so popular most likely because they’re cheap! However, what some people forget is after they’ve bought their goldfish so cheaply, they then have to buy all the equipment that goes with it! This can be more expensive!

Whilst you’re learning all this amazing stuff about goldfish, did you know that the larger species of goldfish can reach over 18 inches (about 45cm) in length! That’s huge! Also, they can weigh up to about 10 pounds, which is the same as a very large watermelon. Or a small microwave oven. Or a small dog. I could go on, I love stuff like this. How can a goldfish weigh as much as a dog? Anyway, the size of the tank that you keep your fish in will have an effect on its growth (to some degree), other factors are how clean its environment is and also its diet.

Anyway, back to it…

Underlying Reason Why Your Goldfish Loses Color

This wouldn’t have happened overnight, of course. You wouldn’t have just woken up one day, gone to feed you fish and thought, ‘hang on, this one’s changed color!’ – it’s a gradual process, but this in itself is part of the problem. As it can be so gradual, it’s difficult to see it actually happening. It’s not uncommon for a fish to change color over time. Sometimes, they can even change into some kind of pattern! So, why is my goldfish turning white?

So, there is usually an underlying reason why your fish have changed color though, have a think about the below possible situations and ask yourself whether any of these could be a factor:

  • Has the water been changed relatively recently and did the process of changing the water differ from previous?
  • Has the water tank been moved?
  • Has the temperature of the water changed over time, perhaps by the tank being in direct sunlight?
  • Have you introduced other fish into the tank?

Aside from this, it could just be that the fish are just maturing into old age (with an associated and connected color change).

Are they Changing Color or Just Losing It?

It should be pointed out here that the fish doesn’t actually change color as such. It would be more accurate to say that it loses its color. Although fish shouldn’t be exposed to direct sunlight, they shouldn’t be kept in the dark. Without light the fish will lose their pigmentation – this is because the individual cells that provide the color of the goldfish have responded to the lack of light and the resulting outcome is the original color is lost.

Typical Cause of Your Goldfish Losing Color

Goldfish turning white (or to be more accurate, losing their color) is actually quite common. The typical reasons why this would happen (in order) is the below, note that it could be a combination of these.

  1. Genetics
  2. The fish are maturing, they have had their fun and it’s time to settle down and get a mortgage. Basically, they’re becoming adults.
  3. Something that is familiar to me the more ‘adulty’ (yes I know that’s not a word) I become, and that’s diet-related.
  4. The quantity of sunlight that the fish is receiving. There’s a direct correlation between the light they receive and how bright their color is. Fish kept in darker conditions will not be as bright.
  5. The quality of the water in which they reside. You need to check your water quality frequently and ensure you have all the bits you need to achieve this. A poor quality environment will cause the goldfish to lose the quality of their color. Here’s a great fish tank test kit. If it’s a filter you need, you could do a lot worse than this. (Both links open a new tab in Amazon).
  6. Disease – note that an ill fish could be caused by one of the above.

So, start from the top and work down – you will get to the bottom of it!

Goldfish Genetics

Another possible reason why goldfish may lose their color is that it has been programmed into their genetics. This usually happens in their first year of life. Nothing you can do about this, it’s just how they are!

So if you’re worried that you’re feeding them the wrong food, your water isn’t quite right or there’s not enough light then it might not be any of these things! Before you start looking into whether the color-loss was caused by you, ask your pet supplier if this is normal for this breed.

Something more serious?

Hopefully, the problem will be down to genetic reasons or something else that you can remedy yourself quite easily. If it’s not obvious you have to consider something a little more problematic.

The most common cause of this kind of color loss within goldfish is related to bacterial infections. Unfortunately, these can be quite serious. You may well see other symptoms of problems within the fish, such as a lack of appetite. There are other issues though, such as tuberculosis which can cause color loss and unfortunately, this can be fatal.

Make sure you keep your goldfish tank nice and clean and check your levels of ammonia and nitrate at least every month.

Color or no color …

The color of your goldfish isn’t necessarily a problem, they can survive just as long without their color as they can with. However, that doesn’t mean you shouldn’t ignore it totally. It could be a symptom of a problem that you will want to sort. For instance, maybe the color change is indicative of the water quality is sub-par. Or maybe your fish isn’t in tip-top condition. Either way, don’t ignore the signs.

Another thing to consider is the food that you’re providing, it might be less likely than the other options but have you changed its diet recently? Make sure you include lots of veggie-type foods and peas.

If they don’t go for it straight away, give them some time – they may need a day or two to become accustomed to the new taste. If they do leave the food though, make sure you remove it before you go to bed to ensure you don’t spoil the water.

Also, consider whether you really want your fish to be back to its original color for the right reasons. Is it just because you prefer your fish to be the ‘right’ color? Your fish changing color may well be just part of its development and its natural flow through life. My point here is, does it really matter? As long as the color change isn’t an indication of something more serious then it doesn’t really matter what color it is, right?

Hopefully, this article will have helped you put your concerns to one side, it’s most likely nothing to worry about but do follow the above suggestions if you can. Enjoy your fish, let your children enjoy your fish but don’t let your cats enjoy your fish! 🙂

If you have had a goldfish that’s lost its color then leave a comment and tell us what you did about it (if anything). Also, if your goldfish weighs the same as a small microwave, I want to see it!


I'm Jane Pettitt, co-owner of Pets Knowledge Base with my husband, Matt. I have a grand total of 50 years’ experience as a pet owner. It all started with a guinea pig called Percy when I was 5 years old and since then I’ve lived with two more guinea pigs, a hamster, mice, a rabbit, a tortoise, a dog and 11 cats. I’ve learned so much about pet care during this time and many of my articles are based on my personal experiences and those of my family and friends .

Recent Content