While it’s common to see goldfish and guppies in one tank, it’s not advisable to keep them together. Goldfish and guppies cannot coexist peacefully and healthily in one aquarium.
Goldfish and guppies are two of the most popular species to add to freshwater aquariums. Not only do they add their own unique colors to aquariums; they’re also low maintenance and quite affordable.
From different temperature requirements to different temperaments, goldfish and guppies aren’t meant to thrive sharing one aquarium, unfortunately.
In this article, we’ll dive deep into the reasons why goldfish and guppies shouldn’t be kept in one aquarium.
Can Goldfish and Guppies Live Together?
The short answer is no. Goldfish and guppies are both peaceful fish species and there are many strategies that you can resort to in order to make them coexist in one aquarium. However, they won’t be able to thrive well as their most ideal conditions won’t be met.
Goldfish and guppies have different needs that should be met. Otherwise, they can suffer from poor health and become susceptible to illnesses.
Here are the reasons why goldfish and guppies shouldn’t live together:
- Goldfish are larger in size than the biggest guppy
- Goldfish and guppies have different water temperature requirements
- They have dissimilar dietary needs
- Goldfish are greedy eaters
- They have different temperaments
There’s a huge difference between the sizes of goldfish and guppies. Even if you get them both at a similar size, the goldfish will eventually outgrow the guppy.
The common goldfish can grow up to 12 to 14 inches. Even the smaller species of fancy goldfish can reach six inches.
The average size of guppies, however, is around 1.5 to two inches long. In some rare cases, they can grow up to three and 3.5 inches.
Because goldfish tend to view smaller creatures as snacks, this size difference can be disadvantageous to guppies.
Water Temperature Requirements
One of the main reasons why goldfish and guppies can’t live together is the water temperature. While goldfish prefer cool water, guppies do better in warm water.
An ideal temperature for goldfish is around 68 and 74 degrees Fahrenheit. This pond fish can tolerate warmer waters, but it might reduce its lifespan.
Native to tropical areas, guppies will grow and thrive in water that’s between 78 and 82 degrees Fahrenheit. If the temperature drops or fluctuates often, they can suffer from health issues.
While goldfish and guppies are both omnivores who will eat about anything that’s offered to them, they have different dietary needs to thrive.
For young goldfish to grow properly and healthily, they need about 40-45% of protein and around 10% of fat in their diet. Once they’ve reached maturity, the protein percentage drops to 30%.
Goldfish are low maintenance when it comes to food. They’ll eat a significant range of food, but they’ll be content and even thrive with just goldfish flakes. These can provide all the necessary nutrients for goldfish
On the other hand, like most tropical fish, guppies thrive best on a high protein and high mineral diet, including live food and fish flakes.
Most of the food recommended for guppies include brine shrimp and worms. These contain from 55 to 70% protein—which is higher than what a goldfish needs.
Goldfish Are Insatiable
Even though goldfish are peaceful creatures, they’re greedy when it comes to food. They tend to devour anything that can fit inside of their mouths, including guppy food.
This could be due to the fact that goldfish don’t have stomachs. Everything they eat passes through their mouths straight to their intestines.
In one aquarium, most guppies can swim fast enough to grab on their feed. Still, it’s impossible to say whether all of the guppies have eaten enough before the goldfish devours everything.
What’s more, this insatiable appetite can lead goldfish to gobble down their aquarium mates. The difference in size becomes more advantageous to goldfish in this regard.
Guppy fry is almost always smaller in size than the tiniest goldfish, making it a well-fitting prey. Once goldfish grow to adult size, they’ll most likely be bigger than adult guppies and may feed on them. This is just how nature works—bigger fish go after smaller fish.
Goldfish and guppies have completely different temperaments. While goldfish are calm, peaceful, and graceful, guppies tend to be feisty and a bit aggressive at times.
Goldfish Are Social Fish
Goldfish are known for their social behavior. Although they can show an aggressive attitude toward newcomers, they get over it pretty quickly.
Some studies have even reported that goldfish can recognize their human owners after a few days.
While guppies aren’t exactly anti-social, they can be a bit too much for goldfish. That’s because they’re active swimmers and move around pretty much all the time.
Guppies Are Fin Nippers
Guppies are often advertised as peaceful fish to add to aquariums. While that’s mostly true, there’s no sugarcoating the fact that they can be territorial and aggressive, especially during mating season.
On a good day, guppies chase each other and chase other aquarium mates. This can be somewhat stressful for the other fish.
On top of that, guppies are known to be quite the fin nippers. They’ll nip the fins and tails of each other, as well as other fish.
Because goldfish are naturally slow swimmers, this makes them easy prey for guppies’ harassment.
Making goldfish and guppies cohabit together isn’t exactly impossible. There are numerous strategies available, and some people have even been able to make it work.
However, these strategies aren’t fair to either fish. Finding a middle ground in water temperature still creates less than ideal conditions for goldfish and guppies.
In addition, when it comes to size and food, goldfish have the upper hand. There’s no guarantee that all guppies will be fast enough to grab sufficient food. They’re also constantly put at the risk of being eaten.
The best option to keep both goldfish and guppies is to get them their own separate aquariums. This way you can provide them with all their needs and prevent any mishaps.