We bought 3 small goldfish from Walmart last night. We poured some tap water in the tank and waited for the chlorine to be released. After 2 hours, we put them in with their water (initially in the plastic from Walmart). The night was very cold even in the hall, say 60 °F (16 °C). In the morning we saw all three almost dead. Although they looked alive from above, they didn't move at all. Their mouths were slightly moving, but they looked like they were dying. Finally all three were fully dead.

What could have been the reason? We thought maybe the low temperature?

At this time of photo, the black one was probably dead. enter image description here

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    did you ask what was needed to keep goldfish in the store.here is a link to get you started fishlore.com/NitrogenCycle.htm for one goldfish you need a tank of 150 liters for the next 50 liters larger and so on(google large goldfish to get a hint about the size you can expect) Jan 2, 2018 at 7:17

4 Answers 4


Welcome on Pets! First of, please research what goldfish need for an habitat before you buy the next ones. Wikipedia is good starting point. Please note that common goldfish can grow larger then 16 inches (30cm).

Size: You will find in short order that the bowl in the picture is way to small for any fish to live in.

Water: If you know that the tap water in your country is not good enough for aquarium fishes, find out how to treat it so you can use it.

Contents: When you have found a suitable size aquarium for goldfishes, you start thinking about the contents, so the fishes will feel save. Sand on the bottom & plants for example. Maybe some rocks. Think about a filter, helps a lot with the water quality over time.

Placement: You will need a place for the aquarium where it doesn't get to warm or cold. Both will kill fish, slowly or outright. It might need cooling or warming, depending on the weather of where you are.

Fish: If all is in order, you wait a bit. Around a month is suggested. This will enable your aquarium to become a stable biodome for your fishes. Then you get the fish you want. Do keep in mind that the oldest recorded goldfish was 43(!) years old. That is longer then a cat or dog!

To answer your question:

In short, there is a lot of things wrong with your current setup for goldfishes. And with the available info you have given I cannot with certainty say what killed your fishes. What I do know is that they would have died anyway, quite soon, in your current setup.

When your photo was taken, all 3 fishes were (more or less) alive: they are still in a good position in the water. Only when they float belly up, lose their color and stop moving you know for sure they are dead.

Please do your research and get the right setup before you buy your next fishes. It can be a (very) rewarding hobby. But do take care of these very nice creatures. And guppies are probably a better fish for a small setup.


You really should have had the tank water set up already for at least a month before purchase, and not with tap water, bottled water or dechlorinated is best. It needs to go through the nitrogen cycle and if it hasn't had the chance the fish would die


First: You don't need to wait 30 days to add fish if you follow what I'm about to tell you.

Second: Goldfish don't have intestinal tracks so what goes in immediately goes out so they are really dirty and shouldn't be kept in a filterless aquarium but if you must keep them in a bowl, do 1. It is NOT true that fish grow to the size of their tanks, their outside body does but their internal organs don't, eventually their organs will get too big for the body and they will die. So it's best to do an inch per gallon. Minimum goldfish should be in a 20 gallon tank but I understand if this is your first time and you want to try things out you will get a bowl. I just want to be clear that if you want to be successful and really love having fish, go bigger with a filter and you won't regret it.

To shortly describe the Nitrogen Cycle to you, the nitrogen cycle happens when you have fish, when you first get a tank it goes through what is called "New Tank Syndrome" during this period of time is when you DON'T want to add fish, the reason being is that beneficial bacteria is needed to start the nitrogen cycle eliminating any toxins such as Ammonia, Nitrites, and Nitrates. Ammonia is the #1 killer of fish so in order for it to be transformed into its lesser toxic state called Nitrate it must have beneficial bacteria in the tank. How do you do this?? Well you can buy beneficial bacteria to start that process.

Say you just started your tank, set it up put all your decor and then water. Instead of putting fish in that day, you can go to your local pet store and pick up beneficial bacteria, I'd suggest API Stress Zyme, you'd also want to pick up Stress Coat which is a water conditioner. For the rest of your fish keeping hobby you'll want to use both whenever doing water changes, whatever bacteria you take out, you must put it back in. So you'll double the dose on your tanks first setup so say you have a 10 gal you'll want to treat it like a 20 gallon. You usually do both Stress Zyme and Stress Coat for the first 3 days THEN bring a sample to your pet store for testing. If all is good then get the fish.

If your fish is at the bottom it means it's stressed out either by being sick, not enough decorations, water conditions, or bullying. Stress Coat is a water conditioner but it also has aloe vera which puts the fishes natural slime coat back on it's body when it stresses out, eliminating any chance of getting sick.

If your fish is at the top gasping for air it means that the ammonia levels are really high. Not to scare you or anything but this is the truth, ammonia burns gills which stops a fish from being able to breathe, which is why you might have seen them at the top or the very bottom.

I would suggest buying a bigger tank, if it can be done get a 20 gal and a Aquaclear filter (Literally the best and will make your life so easy) Get Stress Zyme and Stress Coat, double the doses of both so 2x of 20 ml each or full cap, and let your tank run for 3 days before adding fish.

If that can't be done then still get the Stress Coat and Stress Zyme and if your bowl is 1 gal just double that dose by the instructions on the bottle. Still wait 3 days.

Make sure you keep up on changing your carbon every month if you have filter, you should be doing monthly water changes of 25% or weekly of 10%.

If you decide to get the Aquaclear filter, don't wash the sponge or bacteria blocks in fresh water if they are dirty, instead wash them with the tank water you pulled out during the water change.


Okay, where I live tap water is unsuitable for fish keeping in part due to the chlorine( I think mine us too hard) I suggest you get a water testing kit 2) it takes 24hrs for chlorine to off gas out of water. This link to the homebrew SE has several methods for removing chlorine from water https://homebrew.stackexchange.com/questions/3447/ 3)the correct method for introducing fish to new water is to add 1 cup of the new water to the bag, wait an hour, add a second cup of tank water to the bag. Wait another hour then place fish in tank. It is not recommended that you add the shop water to your tank because of potential pathogens being present. The slow change of water is to prevent your fish going into shock.

I have had my pond freeze over without goldfish dying I don't think the temperature was the problem. I think it was your water and how fast you put them in.

I note that you didn't mention putting Water Conditioner or Stress zyme in or cycling your water before adding the fish. I know the recommendations as adding both to the water at least 3 days before the fish, to allow it to cycle. Giving the good bacteria time to establish and a week being better. This needs to be done for new tank ecologies.

While goldfish are hardy you should still provide a suitable environment with good water quality through proper preparation, somewhere to hide either under plants or plastic structure. A suitable size tank or pond. In the case of a tank it needs a back this is for the psychological health of your fish

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    if you do not cycle the tank the fish will die,cycling is needed to build up bacteria handling the waste and converting it to plant nutrients, here is a link to how it is done fishlore.com/NitrogenCycle.htm Jan 2, 2018 at 7:25
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    @SAM A This answer keeps the myth alive that any fish can reasonably live in a bowl of the grown up body size without any filtration. Like trand hansen pointed out, they need an aquarium with filtration and animal keepers need to gather information and prepare a few weeks before getting the fishs (the links provide all information). Jan 2, 2018 at 8:08
  • Karl, I never used the word "bowl" in my answer. And I did mention needing pretreatment of the water- a specific general treatment and suggested they test to find find if additional tweaking was required I also specifically mentioned adding the bacteria in advance of the fish.
    – SAM A
    Jan 2, 2018 at 10:23

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