Topic: What is the average lifespan of a Molly Fish? How long do they live in fish aquariums on average? Mine seem to keep dying on me and I can’t figure out if it’s something in my tanks or do they just not live a long life? Need help?

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Posted by Nick D: I’ve been keeping mollies for around 20 years and I’ve never had any live for over 5 years. These fish are constantly breeding and any animal on the planet that breeds a lot has a short lifespan. Some people claim they’ve had mollies live for 7 years but.. I don’t believe it. The biggest factors that make them live longer are food quality, Tank size, and good water.

Lifespan of Molly Fish?

The average lifespan of a molly fish is around 2-5 years. You have to remember that these fish are constantly breeding and designed to do just that. Animals that breed non-stop usually do not have very long of a lifespan. Having good water parameters in your aquarium and having live plants in your fish tank will really help. Feed them once a day and an amount in which the fish will consume in a couple of minutes. You don’t want any uneaten food sitting in your aquarium.

two of my mollies are a bit of bullies and will pick on some of the other fish. we had to separate one of our smaller kohaku mollie and a couple guppies from them because our pineapple mollies are just total jerks. after we rearranged things, they stopped. i dont think they do it really out of aggression so much as they seem to do it in a form of aggressive play: they bump and nip at some of the other fish, but eventaully they settled down and left them alone. like a mix of play and/or dominance type of bullying.

So I have a 60 gallon with 5 Angel’s and a red dwarf gourami. Can I add mollies to my tank? I found some dalmatian ones and I really like how they look… but I dont wanna add them if my Angel’s will kill them.

Molly’s are very docile fish, I would not recommend mixing them with an aggressive fish unless you have LOADS of plants and hiding places for the mollies to get away and it’s a very large aquarium.

Angels are semi aggressive but mostly to their own species. They are also slow swimmers so any aggression is usually gone after the other fish swims away. Mollies are definitely not docile, mollies were just as aggressive as my angels especially when in a small group. They can occassionally nip angelfish fins. Don’t keep all males. Try to keep 2+ females per male. The fry can be live fish food.

Hi guys! I’d love some advice  Tank: 5.5g, 2 (was 3) mollies, 2 snails, living plants, gravel substrate, filter,  heater Fish: 1 gold molly, 1 black molly (with a fungus infection), 1 dalmatian molly (passed away) + 1 nerite and 1 mystery snail Help: The black molly has a fungus showing up on her eyes and it appeared the day after the other fish died. Since then the tank was cleaned as much as we could and did a major water change (80-90%). 1 day later the fungus looks like its more attached (not floating and barely hanging on). We added water conditioner today. Will I need to get fungus treatments for the tank or will it resolve over time?  Thanks in advance from the new fish mom!

Well you’re tank is to small for 3 mollies for starters. And being livebearers you’ll have tons of babies before you know it. Was it cycled before you added fish? With your deep clean, you likely destroyed whatever bb you had. How frequent are you water changes?

What’s bb? We’ve had the tank for close to a month and we’ve been changing like a 3rd of the water every sunday. Fish went in the same day we brought the tank home. We were all pretty inexperienced but we’ve been doing so much reading since we brought them home we’re realizing we should have done stuff differently

Get a siphon and a bucket. Or invest in a python. Don’t change filter media and don’t clean your substrate too thoroughly.

Mollies require a little bit of aquarium salt, they are naturally brackish water , I would recommend platies for lower maintenance fish.

I ended up with baby mollies by accident when they hopped in the bag when I was getting others from a miscellaneous tank at the lfs. I just kept them in a small tank, heated and crushed up the food really finely so they could eat it. They’re rather hardy and even went through an outbreak of ich and survived just fine.

Im having the same issue, just had our third batch of fry. From what I can tell the best solution is to either seperate the males and females to eliminate more fry, and possibly find a fish that eats mollies and set up a tank for them.