Molly Fish and Tiger Barbs – Can You Keep Them in Same Aquarium?

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When setting up a community aquarium, finding compatible fish can be a bit of a head scratcher especially if one of the fish species you’re planning to keep has a more difficult temperament.

Tiger barbs aren’t the most docile fish around, and in fact, they can be quite aggressive towards their mates and other fish.

Some of these tendencies can be tempered (I’ll discuss this in a bit), and they can be housed together with other fish in a community aquarium.

I often see the molly fish listed as a compatible tank mate for tiger barbs. But are they? Can you really keep molly fish and tiger barbs in the same aquarium?

Yes, you can keep mollies together with tiger barbs, but with some caveats that I will present to you below.

But before I do so, let’s meet the molly fish and the tiger barb:

Molly Fish


Molly fish come in a lot of varieties, but the most common variety found in the aquarium trade are the short-finned mollies.

Mollies grow on average to 4 inches, they enjoy water temperatures in the 72-78° F range, with pH between 6.7 and 8.7. Some mollies live in brackish waters, but most do just fine in freshwater.

Since they’re very active fish, they need a spacious aquarium that should be around 20 gallons. Careful with male to female ratio, males will pursue females nonstop and stress them out (keep only one male to every two or three females).

Mollies are livebearers, so you can expect lots of fry if you keep males as well. While generally docile, male mollies are known to be aggressive at times, especially when kept together with other males or if they don’t have enough space in the tank.

This is another good reason to offer them ample space in the aquarium. A further reason why a bigger aquarium is best for mollies is that they produce quite a lot of waste.

Molly fish tend to eat a lot on account of being highly active, so keeping the tank clean of toxins is very important, especially when kept together with other fish that might be more sensitive to changes in toxin levels.

I recommend investing in a good water filter to keep the water clean and avoid sudden changes in water parameters.

Because they have quite the appetite and they’re an omnivorous species, mollies are easy to feed. They need foods with a large vegetable fiber content as well like algae and vegetables.

In fact, molly fish feed on algae in the wild and they’ll do a good job at scraping off algae that may naturally grow in your aquarium.

Feed mollies an amount they can eat in about 5 minutes. Offer them high-quality flakes, freeze-dried foods or live brine shrimp, tubifex or bloodworms, and veggies.

Mollies are not aggressive when kept in the right conditions and they are compatible with a lot of fish including guppies, platies, cichlids, gouramis, etc.

Mild fin-nipping may appear between males or when mollies are crammed into small aquariums or kept with incompatible fish.

Tiger Barb


Tiger barbs are semi-aggressive fish that should be kept in large schools (6-10) to temper their aggressive behavior. They especially enjoy nipping at the fins of long-finned docile fish.

This doesn’t mean you can’t keep tiger barbs with other fish species, just that you must select compatible species.

Since they need to be kept in large schools and they like to swim around in the tank a lot, they should be provided with a lot of space to do just that. Therefore, set up a 20-gallon tank for them.

Water should be 75 – 80 degrees Fahrenheit, water hardness of up to 10 dGH and pH of 6-7. This is the ideal range for them, however, slight variations can be accepted.

Planted tanks with driftwood and hiding places are great for tiger barbs, especially while the pecking order in their shoal is being established as weaker members of the shoal may be harassed.

If kept in large shoals, tiger barbs will mostly keep to themselves. But you should still be watchful over them to prevent any fights in the tank.

Tiger barbs feed on an omnivorous diet that should be varied and they’re egg-layers that can be a bit more difficult to breed (conditioning and artificial hatching is required).

How to Keep Molly Fish and Tiger Barbs in the Same Aquarium

Tiger barbs and molly fish are compatible, but their compatibility isn’t 100%. I’d rate it at an 80% seeing how both fish — and especially tiger barbs — have aggressive tendencies.

Therefore, if you want to keep them in a community tank, there are a few things you should focus on to curb any mischievous behavior on both sides:

1.  Set up a roomy tank

If your fish have plenty of room in the tank, they won’t become aggressive as they would in a small, overcrowded tank.

2.  Keep them in numbers they feel most comfortable with

The more tiger barbs in the school, the less aggressive they are. Avoid keeping multiple male mollies together and respect female to male ratio recommendations.

3.  Favor short-finned mollies over long-finned ones

Choose molly varieties that have short fins and avoid adding long-finned mollies to the community tank that houses tiger barbs.

4.  Keep water conditions in optimal range

Make sure water parameters are within the accepted range for both species.

5.  Keep an eye on the aquarium

Don’t ignore signs of aggression or injuries that appear out of nowhere. Watch over your fish to see how they interact and if they get along well.


If you meet these conditions, it’s unlikely that molly fish won’t get along with tiger barbs. There is no 100% guarantee for fish compatibility. So make sure you do everything you can to temper the behavior of fish with known aggressive tendencies.

A spacious tank, good water conditions, and species-specific keeping requirements can all help to make your community tank a peaceful and happy one.

Tiger Barb Image:

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
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