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

When searching for new tank mates for your fish, compatibility is the key to having a healthy community of fish.

Fish that enjoy the same water parameters and have similar temperaments qualify as great companions for each other.

Because temperament incompatibility tends to be a deal-breaker, I often get questions on whether you can keep molly fish and tiger barbs together since tiger barbs aren’t as docile as mollies.


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Despite being temperamentally different, molly fish and tiger barbs can be kept in the same aquarium if certain conditions are met.

To find out which are the conditions that make tiger barbs and molly fish compatible, I encourage you to read the guidelines below in how to keep mollies and tiger barbs together.

Molly Fish and Tiger Barbs – How to Keep in the Same Fish Tank?

Molly fish are more peaceful as opposed to tiger barbs that are known to have a semi-aggressive temperament, which can be managed in the right conditions.

Here’s what you should do to make sure your tiger barbs and mollies get along:

1.  Choose Short-Finned Mollies Over Long-Finned Ones

One of the things that trigger tiger barbs to act a bit aggressive is long, flowy fins that they just can’t resist nipping at.

Some molly varieties are long-finned, which is a big no-no when housing tiger barbs too as their curiosity will get the best of them and will nip at those fins.

Therefore, don’t choose to keep sailfin mollies with your tiger barb, and opt instead for short-finned mollies.

2.  Pick the Right Tank Size

Molly fish average at around 4 inches in size, while tiger barbs are smaller averaging at around 2.5-3 inches.

Both fish require space in their aquarium not only because they’re active fish, but also because they like to be kept in groups.

For tiger barbs, it’s especially important to be kept in larger groups, otherwise their aggressive tendencies will start to surface.

A 20-gallon+ tank is an excellent option for these fish, especially that both enjoy a planted aquarium and having life plants in the aquarium cuts down on how many fish you can comfortably keep in it.

Therefore, either go for a bigger aquarium or cut down on the number of fish you’re going to keep all the while observing their stocking requirements.

3.  Pick the Right Number of Fish

Tiger barb fish should be kept in a large school, where they can establish a pecking order and generally mind their own business. For this, however, you’ll need to keep them in a group of 6-10.

If kept in a large school, it’s less likely for them to exhibit aggressive tendencies towards other fish and will generally keep to themselves.

Picking the right number of fish also means not overstocking the aquarium. Overstocking has multiple unfavorable consequences such as lack of enough oxygen, fights and aggressiveness among fish, quick accumulation of waste, etc.

4.  Make Sure Water Parameters are Optimal for Both

It goes without saying that water parameters should match for both types of fish. Mollies enjoy water that has a temperature in the 72-78 F range, while tiger barbs enjoy very similar temperatures 75-80 F, allowing you to find a “sweet spot” that works for both types of fish.

Their water pH requirements are also similar — between 6.7-8.7 for mollies and 6.0-7.0 for tiger barbs.

Since both fish enjoy warmer waters, you should have an aquarium heater installed, which will help keep the temperature stable and at the required level.

5.  Do Frequent Water Changes

Water changes are crucial in any aquarium, but in one that also houses mollies is even more important as molly fish have a high bio-load.

Water changes will help dilute toxins and remove debris, thus refreshing the water and keeping parameters in check. Do install an aquarium filter too, which will help reduce pollutants and keep the water clear.

6.  Population Control

Tiger barbs are egg-layers, which aren’t too difficult to breed, but they also don’t breed as readily as molly fish do.

So, when it comes to tiger barbs, there’s no need to worry much about population control, especially that they’re unlikely to breed in a community aquarium.

With mollies, however, things are a bit different. Molly fish are live-bearing fish that breed often (they can breed as often as every month) and produce a lot of fry.

Therefore, if you’re keeping both male and female molly fish in your aquarium, make sure you limit the number of males. Keep a single male for three females.

Now, if you’re thinking not to keep males at all, it’s not 100% it will solve the issue of breeding for you since female molly fish can store the sperm of the male molly for quite a long time, and they’ll go on producing fry even without a male.

In this context, it’s perhaps wiser to keep male mollies only instead of having fish from both sexes.

7.  Feeding

Feeding isn’t an issue with these fish. They’re both omnivorous and they’ll both take and feed on any fish food that you offer them.

That said, I really encourage you to set up a feeding schedule (one or twice a day), offer them a variety of foods (vegetable matter is important for both species!) and avoid overfeeding them.

Small amounts they can eat in a couple of minutes is enough to keep them healthy without overfeeding them, which not only that it fouls the water, it’s also a health hazard for your fish.


Since they’re some caveats when keeping molly fish together with tiger barbs, their compatibility isn’t 100%.

Because of this, it’s important to think about the guidelines that I proposed for keeping these fish together to see if you can meet their needs, so that you won’t encounter problems in your community tank.

If you meet the requirements of your fish, keep them in the right number and you offer them the right conditions for coexisting, you shouldn’t have problems keeping them together.

However, if at any point you see signs of aggression, make sure you remove aggressive fish or separate your fish to avoid injuries and further damage.

Tiger Barb:

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