What is the perfect water temperature for a goldfish?

Shutterstock.com/ Mirek Kijewski

Goldfish are one of the most common pets in the world with over 480 million sold every year. The goldfish is a fantastic first pet for a child as it will start to teach them the responsibilities of looking after a living thing with a large margin of error and little mess to clean up. However, there are some things you need to be careful about when having a goldfish as a pet with the water temperature something that is often forgotten.

The reality is that goldfish are pretty easy-going fish. They are happy to survive in room temperature water meaning that the majority of the time, they are happy in the water they are in. However, you must be careful when the summer heat is raging as if the room is too hot, the water will be too hot too. This is not good for your fish.

If the temperature in your room goes above 32 degrees Celsius than it is not good for your fish and is far too hot. A temperature of around 21 degrees is ideal for goldfish and they will be happy all year round in these conditions. Goldfish actually enjoy a freshwater swim so it will relish anything from almost freezing to 29 degrees. In close to freezing conditions and close to 30-degree conditions you will notice that your goldfish is swimming a lot slower. Find the right temperature and you will see an excited little fish.

It is pretty obvious that goldfish do not enjoy freezing water and while we are sure that the water in your home is unlikely to freeze, it can happen in outdoor ponds with goldfish too. If this happens your fish should be ok. If a pond starts to freeze a goldfish will swim to the bottom of the water and will be ok. A fish that is 3 feet or more in-depth will be enough for a goldfish to hibernate through the winter in. However, if the water is too cold and it freezes entirely or if the water is so shallow that it freezes entirely, the goldfish will freeze too. This is clearly a disaster unless you have a resurrecting fish.

If you really want to spoil your fish it is a nice idea to take a quarter of the water out of the tank at a time and replace it with cold water. This will give the water a refreshing boost that your goldfish will thoroughly enjoy. 

The only other aspect you need to consider with water temperatures and goldfish is if you are trying to breed them. Goldfish are predisposed to an outdoor environment so they will start to breed as cooler water becomes warmer. If you want to breed goldfish you should hold the temperature as low as 5 degrees celsius for a few days and then replace it with water of around 21 degrees (or room temperature). This will convince the goldfish that the harsh temperatures are gone and that it is the perfect time to make some baby goldfish. 

The reality is that that majority of the time you do not have to worry about water temperature at all, which is why it is such a good fish for a child to look after. Not only that but goldfish are friendly fish too, so they can be put in a tank with most other breeds. Saying that, be careful with the fish you choose. If you pick something as small as a guppie it may become goldfish food and if you choose another fish that is too aggressive your goldfish will suffer.