Do Molly Fish Die Easily? A Detailed Article

Molly fish are freshwater fish that will happily live in a wide range of water parameters. Honestly, you can never get enough of molly fish as long as you understand their uniqueness and adapting nature. You can even keep these mollies in saltwater, and these brackish water-originated fish will not utter any complaints. But then again, there are instances when you look over to your aquarium and see molly fish dropping dead one after another as if it is a mere game. Do molly fish die that easily? Or is it something we often miss leading to their death?

Molly fish die easily when they feel stressed due to pollution exposure, incompatible tank mates, and unfavorable tank conditions. Usually, the average lifespan of these fish is about 3 to 5 years. So, anything less than this is an untimely death that often happens due to your carelessness.

But trust me, they will die within a month or two even though Molly is one of the hardiest fish you can get. These mollies will live in saltwater while silently accepting freshwater too. You are one lucky aquarist if Molly is the first fish you’ve ever owned, as they will lead to the experience of raising both freshwater and saltwater fish at a lower price.

I know I have made you even more curious or confused, but brace yourself; we are here for a ride, aren’t we? Let’s learn more and know all that might lead to heartbreak and death.

Do Molly Fish Die Easily?

No, molly fish are hardy enough to survive the minor fluctuation or problem in the tank. So, these mollies do not die easily and do not believe anyone who says otherwise.

Here is the thing, these fish are a wonderful package that will show you how diverse they can make your aquarium. But that doesn’t mean they won’t die out of a sudden.

I am not saying they will die easily; I mean that various factors will kill your fish without you realizing it. For example, fluctuation in the water temperature, pH, algal bloom, ammonia poisoning, nitrite poisoning, and various diseases in molly fish are some of the prime suspects for their death.

But then again, you can control most of these causative agents from killing your molly fish. And trust me, it won’t give Molly an easy or fast death.

So, I won’t say molly fish die easily, but they can die suddenly within days. So, it would help if you got extra careful when you start seeing changes in molly fish behavior.

How Long Will Molly Fish Live?

You might already know the lifespan of molly fish, now don’t you? But here is a quick recap: your wonderful fish can live up to 3 to 5 years, depending on how you take care of these fish.

You can expect a molly to live its fullest span when the tank is like a welcome part for all the germs and bacteria.

Molly fish have a similar lifespan in the wild and in captivity, but it all comes down to the care level and tank maintenance.

Also, don’t be that hard on yourself; sometimes, death is inevitable. You might not realize the lifespan of your molly fish, and they might have already lived five years of their life.

So, it’s okay, and death is not the world’s end. But, you need to make sure your molly fish are happy when still alive.

Molly Fish Death: Why Do Molly Fish Die Easily?

Molly Fish will die easily if humans take too many Molly fish or if there is habitat destruction. They will die easily because of the following:


Pollution in the water causes these fish to get sick from it, which leads fish to die easily. So Molly fish need clean water, or else they will get sick from the pollution, and then they will become weak because of that, which can lead to their death.

These are susceptible to pollutants and chemicals from pesticides, fertilizers, detergents, and other waste products (eutrophication). This pollution causes Molly fish to get sick, reproduce less, and die off. 

Ammonia poisoning in the aquarium can make your fish suffer from the worst acidic burn and poisonous stings.

You might even see molly fish jumping out of the tank or gasping for breath when there is something wrong in the tank.

Also, various chemicals and changes can bring swim bladder disorder in molly fish, including other diseases that eventually kill them.

Incompatible Tank Mates

Can you imagine being chased all day or all the nipping and nagging without a break? An incompatible tank mate can make the life of molly fish worst than you think.

All in all, these molly fish will hide to save themselves from all the nibbling, chasing, and all the pushing, and pulling.

You might not know but the attacks from tank mates can result in injuries and open wounds that will invite bacterial and viral infection in molly fish.

These wounds and infections can kill your molly fish within a few days and also the attack itself can get fatal after a while.

Also, if the tank mates are predators that can easily fit molly fish in their mouth, it is a gone case. You won’t see your fish ever again or you might witness the predator munching your molly happily.

Repeated Pregnancy

Pregnancy is a huge thing even when it comes to small fish like mollies. You cannot imagine the toil and hardships molly fish go through while carrying fry in their belly.

Molly fish are livebearers that will give live birth to small baby mollies in the tank. It is easier to lay eggs as eggs are comparatively smaller than fry.

Mollies give birth to nearly 40 to 60 fry in each pregnancy and they can get pregnant immediately after giving birth as well.

Now, imagine, giving birth to these many fry without proper care and attention. Your molly fish give live birth and ends up sensitive and vulnerable to any water changes or stress from other tank mates.

A weak immune system after pregnancy can result in diseases and illness in these molly fish which will eventually lead to their death.


Some Molly Fish might be diseased. When Molly fish have diseases, they can spread to the whole population, which causes Molly fish populations to decline because of too many Molly fish dying off.

Molly fish are sensitive creatures, so if a Molly fish dies, Molly Fish might give diseases to the other Molly fish in their habitat.

In addition, Molly fish are empathetic creatures, so if they get sick from being with other Molly fish who has a disease, it can kill them easily and spread the disease around.

How To Keep Molly Fish Healthy?

Molly fish are sensitive to a variety of factors. Molly fish need the correct water temperature, PH balanced, and oxygen levels for their health.

Establishing good Molly Fish habits early on will ensure that they live long, healthy lives even in challenging environments like low-quality habitats or overcrowded tank conditions.

However, some ways to keep Molly fish healthy are:

Perfect Environment

Molly fish are sensitive to the environment. Therefore, they need clean, well-oxygenated water at a comfortable temperature (they prefer temperatures in the 65°F-80°F).

In addition, these fish need their tank or habitat to be free of ammonia and nitrites as these substances can poison Molly fish very quickly if they build up enough.

Molly Fish Diet

It would be best to feed Molly Fish a varied diet of live plants, algae, and vegetables. They are omnivores, so they need to eat both plant and animal-based matter to get the nutrients they require for life.

Feeding your Molly Fish with this variety will give them all the nutrients they need for health from all the food groups.

Breeding Molly Fish

Breeding Molly fish can be tricky, but it is easier than one might think! You need a male and female molly fish and a breeding tank to breed Molly fish. Of course, you should keep Molly fish in good health before the breeding process.


Molly fish are sensitive creatures who require careful care to stay healthy. They can get sick from many factors, such as poor water quality or other diseases they might have picked up elsewhere.

You should always clean tank water to free them from ammonia and nitrites. These substances will poison Molly fish quickly if they build up enough in their habitat or tank environment.

Tank Size

The tank size is important because it affects how much oxygen there is available, which will affect a Molly fish’s health. Molly fish need to have a lot of space in their habitats or tanks.

Molly Fish are social creatures and live best when together with other Molly Fish, so you must give them enough room to swim without bumping into one another constantly. This will make Molly fish happier, but it will also help Molly Fish grow to its full potential.

Water Changes

Molly fish need water changes to maintain good PH levels. However, they also have sensitive gills that absorb oxygen from their environment through their skin, so changing your Molly fish water often is important.

They are sensitive creatures, and they need clean water. So you can clean a Molly fish tank with warm, fresh water at least once a month or more if needed.

Be sure to replace 50% of the tank’s volume with new water when doing this process so that you do not shock Molly Fish by changing their chemical levels in a too drastic way.

Some FAQs

What Is The Best Food For Molly?

Feed Molly fish live foods like micro worms, pellets, flakes, veggies like cucumber, zucchini, etc., and bloodworms.

They also do well with dried shrimp or any frozen food appropriate for Molly’s size. They enjoy variety, so feel free to mix up their diet as much as possible (don’t overfeed them).


Molly fish are not difficult to maintain. Unfortunately, they do die easily; however, this rarely happens, and when it does happen, Molly will often be sick or injured beforehand.

To keep Molly healthy, there should always be a clean tank with water conditions such as temperature, ammonia levels, and pH levels at acceptable ranges for them to survive in an environment that has food (fish flakes) on one side of the tank and hiding places on other sides of their tanks where they can find shelter from predators like larger fish who want to eat those little mollies! 

Drop them in the comment section below if you have any questions or queries. I will get back to you once you.

Good Luck!!

Happy Fishkeeping!!