Guppies and cory catfish are among the most popular freshwater fish kept in home aquariums. This, of course, raises one question: can they live together?
A few years ago, I thought that my guppies were too aggressive for corydoras. However, as I gained more and more experience in this field, I found that it was just the opposite.
In this article, I will show you why cory catfish can live with guppies in the same tank. I will also explain how many of them you should get, and how to grow them properly side by side.
Let’s dive right into it.
Can Cory Catfish And Guppies Live In The Same Tank?
Yes, cory catfish and guppies can live in the same tank. These two species have a lot working in their favor, including:
1. Both Corydoras And Guppies Are Peaceful
Cory catfish are peaceful. They can’t help it.
Even if they wanted to antagonize their neighbors, the creatures have downturned mouths that do more sucking than biting.
They don’t pose a threat to guppies. But what about the guppies?
While they are more likely to misbehave when exposed to the wrong conditions, you can trust guppies to maintain a peaceful demeanor in a clean, well-maintained tank.
2. They Share Similar Water requirements
Cory catfish and guppies thrive in the same environments.
They can tolerate temperatures of 72 to 82 degrees F, pH of 7-8, and water hardness of 5-19dGH (Corys) and 8-12dGH (Guppies).
You don’t have to antagonize guppies by altering the conditions to make cory catfish happy or vice versa.
This is good because fish can become aggressive when you force them to endure the wrong parameters.
3. Corys And Guppies Are Close In Size
Guppies have an average size of 2 inches. This is encouraging because corys can grow to a size of four inches. Guppies cannot confuse them for food.
You would have a reason to worry if the guppies were larger because negative stimuli can encourage the species to manifest aggressive tendencies.
Cory catfish are different. They respond to bullies by running away and hiding. Therefore, you can trust a larger cory catfish to live peacefully with a smaller guppy fish.
How Many Guppies And Cory Catfish Should I Get?
The short answer: six cory catfish and at least four guppies (three females for each male).
Cory catfish are easier to accommodate. They require a group of six or more to live happily in an aquarium with other fish.
Stefano Marras and Paolo Domenici performed a study analyzing the behavior of schooling fish.
While highlighting the fact that fish in a school do not move in random order when they encounter a threat, the researchers noted that shoaling behavior appears in various species in the animal kingdom.
In other words, the behavior is not unique to fish. And in all cases, the goal is to evade predators.
Cory catfish are too peaceful and timid to live alone in an aquarium filled with guppies. Keep them in the largest group your tank can hold.
Guppies are complicated because they have a playful temperament.
They will only maintain their peaceful behavior if you keep them in a group of three to six while maintaining a ratio of three females to every male.
Male guppies become aggressive when you force them to fight for the few females in the tank.
They may turn that aggression against other fish, including your corydoras. That is unless you satisfy their desire to mate.
The female guppies won’t survive the onslaught. The males are more than capable of harassing them to earth.
A study in the University of Chicago Press Journals found that female guppies in the wild were willing to venture into deep waters populated by predators to avoid the harassment of their male counterparts.
This shows you how disruptive male guppies can become if they don’t have a fitting number of female companions.
What Should I Feed Guppies And Cory Catfish?
Cory catfish and guppies are omnivores. In other words, they can survive on the same plant and animal-based diet.
Feel free to feed them everything from bloodworms and brine shrimp to mosquito larvae and flakes.
You will appreciate the catfish’s scavenging habits. They will sweep the substrate in search of leftovers. The creatures are too gentle to compete for food with their neighbors.
Pro tip: Cory catfish need to eat food that sinks to the bottom. Floating food forces them to swallow air, and possibly develop swim bladder disease.
How Do I Make Cory Catfish And Guppies Co-Exist?
You can maintain a happy, healthy cory catfish/guppy tank by taking the following precautions:
1. Make Sure The Tank Is Large Enough
Ronald G. Oldfield published a paper in the Journal of Applied Animal Welfare Science. He wanted to study aggression in common aquarium fish.
Ronald highlighted what every aquarist knows. Small aquariums attract aggressive behavior.
You need a large, complex habitat to maintain peace between cory catfish and guppies. Aim for a minimum of 20 gallons.
2. Choose The Right Numbers
Make sure each male guppy has at least three female guppies to mate with. Otherwise, violence may ensue, possibly killing your guppies.
If you prefer to keep your guppies from breeding, you can introduce only females, but never put only males in the tank.
A study from the Biological Sciences Department, Califonia Polytechnic State University was trying to understand the impact of various light environments on guppy behavior.
They noted that male guppies were more aggressive in the absence of females. Keep that in mind while populating your tank.
Additionally, don’t assume that removing the male guppies will solve your problem.
A study in Ethology that explored the interactions among female guppies found that larger females had a tendency to dominate their smaller counterparts.
Therefore, you cannot eliminate the possibility of aggression by only keeping one gender.
3. Feed Them Properly
Make sure the guppies are well-fed. They are less patient with insufficient food because they can’t scavenge like the cory catfish.
Give them a balanced diet consisting of brine shrimp, flakes, pellets, blanched cucumber, boiled peas, tubifex worms, and more.
As a rule of thumb, give them the amount of food they can finish in two minutes. This will minimize leftovers, debris, and fish waste.
4. Keep The Tank Clean
You need a pristine tank. It is not enough to maintain the correct parameters. Keep the water clean by performing weekly water changes of 15 to 20 percent.
This is important because adding a group of six corydoras and four guppies may overpopulate your tank, increasing toxins like ammonia.
This could even lead to ammonia poisoning and possibly dead fish. You will also find yourself dealing with more algae than usual, as they feed on nitrates.
You should also focus on installing a decent filtration system, using water conditioners to neutralize toxins, removing dead plants and animals before they rot, etc.
What Else Can Live With Cory Catfish And Guppies?
If you want to add more species to your Cory Catfish/Guppy tank, some common options include:
- Platies – small, peaceful, and boasting the same dietary requirements as guppies and cory catfish. Just make sure you introduce female guppies. Otherwise, the males may chase the female platies to mate.
- Mollies – Any tank that supports platies will also accommodate mollies because they have similar requirements.
- Kuhli Loach – peaceful, small, and capable of surviving in a 20-gallon aquarium. And even though both are bottom dwellers, loaches can live peacefully with cory catfish.
- Honey Gourami – They live in groups of six or more. As such, you may require a bigger tank.
- Otocinclus Catfish – This mild-tempered fish is too docile to bother your cory catfish and guppies.
- Bristlenose Plecos – This is a peaceful bottom feeder that tends to stay out of the way. They will happily share a tank with guppies. They can also live peacefully with corydoras.
- Cardinal Tetra – This small colorful fish lives in groups of 7 or more. You need at least 30 gallons to keep the species happy.
- Neon Tetra – tiny, non-aggressive, and capable of surviving on the same diet and living peacefully with cory catfish and guppies.
- Swordtails – These 3 – 4-inch fish don’t occupy the same aquarium level as cory catfish. Therefore, you don’t have to worry about these two species antagonizing each other.
- Cherry Barbs – These are small, shy fish that can’t tolerate aggressive tankmates.
- Shrimp – Species like Ghost shrimp, Cherry shrimp, and Amano shrimp will happily live with cory catfish and guppies. However, baby shrimp might get eaten.
- Snails – While many aquarists believe that cory catfish will eat snails, this is not entirely true. They may eat baby or dead snails, but mature snails will do just fine.
It shouldn’t be difficult to raise cory catfish and guppies in the same tank. Both species are considered hardy and peaceful.
The main thing worth considering is the male-to-female ratio. To keep a calm environment, I suggest picking three female guppies for each male.
This will reduce stress and avoid unnecessary conflicts. And if you want to diversify your tank, you can also choose species such as platies, mollies, shrimp, snails, etc.