Yes, mollies and zebra danios can live together.
The size difference is a slight concern. However, the similarities in temperament and water parameters will mitigate some of the risks.
Both species are easy to care for, which is why they appeal to brand-new aquarists.
They will thrive in one another’s company, assuming you have an adequately sized aquarium to house them. Nothing triggers violence faster than a crowded tank.
Can I Keep Molly Fish And Zebra Danios Together In The Same Tank?
Some people house these species in the same aquarium because they can’t afford additional tanks.
But does it make sense to pair them deliberately? Yes, it does. Neither species is particularly difficult to rear.
They don’t have unique demands, requirements, or diseases that make them a headache for you or a threat to one another. The size difference is not as big of a problem as you think.
Yes, fish are opportunistic feeders that eat whatever fits in their mouths, and zebra danios are tiny. They rarely exceed two inches.
On the other hand, some mollies are six, seven, or even eight inches long. However, the average freshwater molly fish is just four inches.
The size difference is not significant enough to upend your aquarium. But if it matters to you, take your 8-inch Danios back to the shop and replace them with 2 or 3-inch Danios.
Also Read: 19 Great Molly Fish Tank Mates
Molly Fish vs. Zebra Danios: Behavior
The behavior determines whether or not two fish species can co-exist.
You can’t place aggressive fish in a tank with peaceful neighbors or vice versa. One species will harass the other to death.
Fortunately, the behavior is not a challenge where mollies and zebra danios are concerned. If they fail to co-exist, it won’t be because of their temperaments.
But you can never rule out aggression because fish have distinct personalities, and some of them may choose to misbehave for no apparent reason.
Molly Fish: Natural Behavior
Molly fish are great additions to community tanks because they can hold their own against aggressive neighbors.
The creatures are peaceful. But you wouldn’t call them timid. They don’t mind fighting back when they encounter bullies.
However, that doesn’t mean they will look for trouble.
At their core, mollies are friendly and social fish that thrive in groups. If you’ve noticed violent tendencies in your mollies, something has gone wrong.
Take it as a sign of poor conditions in the aquarium.
Maybe the ammonia concentration spiked because of rotting organic matter in the water, or the tank was too crowded. Mollies won’t misbehave unless you give them a reason.
Zebra Danios: Natural Behavior
Zebra Danios have two significant weaknesses. The creatures are too peaceful to antagonize their neighbors deliberately.
However, a Zebra Danios’ playfulness and boisterous attitude may rub some species the wrong way.
The fish are too fast, active, and energetic for slow-moving neighbors that gravitate toward calmer environments.
Additionally, Danios are fin nippers. Does this make them a threat to the community tank’s peace? Probably not. Molly fish can tolerate the Danios’ antics.
Again, violence will only break out when something goes wrong, such as sudden fluctuations in the parameters or limited food supplies.
Ideal Parameters For Molly Fish And Zebra Danios
| Parameters | Temperature | pH | Hardness |
| Molly Fish | 72 to 80 (F) | 7.5 to 8.5 | 15 to 30 dGH |
| Zebra Danios | 70 to 75 (F) | 6.5 to 7.2 | 5 to 19 dGH |
Molly Fish: Ideal Parameters
Mollies come from warm water bodies in the wild, which is why temperatures of 80 degrees F or even higher are acceptable.
Although you should endeavor to stay in the 70s to keep the mollies happy. The molly fish type will determine the exact parameters.
But most tend to fall within the 72 – 80 F range. Don’t forget to acclimate new mollies to the conditions in your home aquarium.
Otherwise, the stress may kill them regardless of how well you’ve maintained their aquatic environment.
Zebra Danios: Ideal Parameters
A zebra Danios’ 70 – 75 F range seems narrow. However, you shouldn’t underestimate these creatures.
The water they inhabit in the wild can exceed 82 degrees F in the summer. It can also fall below 60 degrees F when winter rolls around.
Zebra Danios are hardier than they look.
They can live in the varied conditions they may encounter in a molly fish tank without succumbing to stress and deadly diseases. But again, proper acclimation matters.
Molly Fish vs. Zebra Danios: Ideal Water Conditions
| Requirements | Molly Fish | Zebra Danios |
| Ammonia | 0ppm | 0ppm |
| Nitrite | 0ppm | 0ppm |
| Nitrate | Less than 20ppm | Less than 20ppm |
| Tank Size | 20 gallons | 10 – 20 gallons |
| Foliage | Yes | Yes |
| Decorations | Yes | Yes |
| Filter | Yes | Yes |
| Heater | Yes | Yes |
| Salt | Where Necessary | Where Necessary |
| Pump | Yes | Yes |
| Lighting | Moderate | Moderate |
Molly Fish: Ideal Water Conditions
Like Danios, mollies are highly adaptive. Give them an adequately sized tank with a decent filtration system to remove waste and stable parameters, and they won’t complain.
Despite their hardy constitution and bold personalities, they can still fail prey to stress unless they have sufficient foliage and decorations.
Fish need to know they can hide if they encounter predators. More importantly, decorations create opportunities for exploration.
While mollies can live in brackish water, they don’t need salt in their aquarium water to stay healthy. But you won’t harm them by adding salt if you follow the dosing instructions.
Zebra Danios: Ideal Water Conditions
Zebra Danios are active creatures. Therefore, they need as much room to explore as you can give them.
They will also appreciate the presence of tall plants and decorations. You need all the standard equipment, including a filter, bubblers, lighting, and heaters.
The goal is to create and maintain the relevant parameters. Fluctuations are just as dangerous to a zebra Danio as the wrong parameters.
Like the mollies, you won’t harm the Danios by adding aquarium salt.
In fact, it may keep some diseases at bay. But you need aquarium salt in particular, not table salt. Both species will appreciate weekly water changes (10 percent).
The Dietary Requirements Of Molly Fish And Zebra Danios
| Food | Zebra Danios | Molly Fish | Quantity | Schedule |
| Fish Pellets and Flakes | Yes | Yes | Small Pinch | 7 Days |
| Tubifex Worms | Yes | Yes | Small Pinch or Less | 2-3 Times Weekly |
| Bloodworms | Yes | Yes | Small Pinch or Less | 2-3 Times Weekly |
| Brine Shrimp | Yes | Yes | Small Pinch | 1 – 2 Times Weekly |
| Vegetables | Yes | Yes | Small Pinch | Twice Daily |
| Daphnia | Yes | Yes | Small Pinch | 1 – 2 Times Weekly |
| Mysis Shrimp | Yes | Yes | Small Pinch | 1 – 2 Times Weekly |
| Maggots | Yes | Yes | Fish can eat their weight in maggots | 2- 3 Times Weekly |
Molly Fish: Ideal Dietary Requirements
Mollies eat algae, invertebrates, and plant matter in the wild. But in an aquarium, flakes, and pellets are more than enough if they have sufficient nutrients.
If you have the time, you can buy or prepare broccoli, cucumbers, vinegar eels, micro worms, brine shrimp, etc.
Zebra Danios: Ideal Dietary Requirements
Zebra Danios will eat everything a molly fish likes because both creatures are omnivores that consume animal and plant matter.
It only takes a few pinches of food to fill them. Excess food will lead to bloating.
They should eat once or twice per day. Feed them food they can finish in three minutes or less. You should also give them high-protein meals once or twice per week.
Ideal Tank Size For Keeping Molly Fish And Zebra Danios Together
Try to keep both species in groups of six or more. That means buying a tank of at least 20 gallons.
Don’t forget that Danios are active swimmers that require ample space. Account for the plants and decorations while calculating the size.
Best Tank Mates For Molly Fish And Zebra Danios
If you’re looking to add more variety to your aquarium, keeping only mollies and zebra danios might become monotonous.
However, if you have a tank capacity of 20 gallons or larger, you can other options. Here are some peaceful types that are compatible options for your tank:
- Guppies
- Ember Tetras
- Rosy Barbs
- Rummy Nose Tetras
- Minnows
- Swordtails
- Gouramis
- African Dwarf Frogs
- Cory Cats
Also Read: Can Molly Fish And Cory Catfish Live Together?
Fish To Avoid With Mollies And Zebra Danios
On the other hand, it’s best to avoid adding aggressive species. I strongly discourage including:
- Betta fish
- Jack Dempseys
- Goldfish
- Electric Blue Acaras
- Green Terrors
- Rainbow Sharks
- Angelfish
Also Read: Do Angelfish And Mollies Get Along?
Conclusions
For those of you who are in a rush, here is a brief summary of what I discussed earlier:
- Molly fish and Zebra Danios can live together harmoniously in the same tank due to their compatibility in terms of temperament and water parameters.
- The slight size difference between Molly fish and Zebra Danios is not a significant concern and can be managed by choosing appropriate individuals or adjusting tankmates.
- Both species, Molly fish and Zebra Danios, are beginner-friendly and easy to care for, making them suitable choices for new aquarists.
- Providing an adequately sized aquarium is crucial to ensure a peaceful coexistence between Molly fish and Zebra Danios, as overcrowding can lead to aggression and stress.
- Recommended tank mates for Molly fish and Zebra Danios include Guppies, Rosy Barbs, Cory Cats, and other peaceful species, while aggressive species like African Cichlids and Tiger Barbs should be avoided.