Yes, Mollies can live in a cold water tank, but this isn’t their ideal condition so they can survive, but they won’t thrive.
As tropical fish, Mollies prefer warmer water with a temperature range between 71 and 85 degrees Fahrenheit. But mollies are also hardy fish, so they can adapt to lower temperatures.
However, if the water temperature drops below 68 degrees Fahrenheit, mollies will become prone to diseases, their breeding will be hindered, and their growth will be curbed.
Mollies are one of the most popular fish options among beginner fish keepers and freshwater aquarists. This is because Mollies are friendly, low-maintenance fish that are quite adaptive to different conditions and are easy to breed.
Mollies come in multiple variations with a range of color combinations -mostly shades of orange and black-. They’re also members of the livebearer family and love to munch on algae.
All these reasons make them one of the most common fish kept as pets. You may be wondering how demanding their tank requirements are or you may be thinking about pairing them with a cold water fish (such as goldfish), so you’re asking “can Mollies live in cold water tanks?”
In today’s article, we’re sharing a detailed answer by discussing the ideal water temperature for mollies as well as how higher and lower temperatures can affect them.
Can Mollies Live In Cold Water Tanks?
As a tropical fish species, any Molly prefers a warmer tank where the water temperature ranges between 71 and 85 degrees Fahrenheit.
That said, mollies are known to be quite hardy fish. This means they can adapt to various environmental conditions that aren’t exactly favorable — one of which is water temperature.
If you’re wondering whether or not Mollies can live in cold water, the answer is yes. They’re sturdy like that.
The keyword in this question, however, is live.
While Molly fish can indeed live in a cold water tank in the sense that they won’t roll over and die, lower temperatures aren’t ideal for them and the fish won’t thrive. They’ll just survive.
As such, if you’re asking “should Mollies live in cold water tanks?”, the answer would be no because your fish will live but not flourish. This would simply be poor practice on the fishkeeper’s side as lower temperatures will negatively affect the fishes’ health, growth, and breeding.
It’s also worth noting that the lack of stability of the water temperature can affect Mollies more than the lowering of the temperature itself. This means that an unexpected and drastic drop or increase in the water temperature can harm your Mollies more than if you keep them in a cold water tank for a long time.
Is a Heater Necessary for a Mollies’ Tank?
Based on the information above, we can conclude that the use of a heater in a Mollies’ tank depends on whether you’re looking to have your fish live or thrive.
We already established that Mollies are robust fish, so they can survive in lower temperatures without a heater but they may not thrive. This is why using heaters for Mollies is recommended.
But if you live somewhere with a tropical climate, your Mollies can thrive supported by the warmth of the ambient temperature as long as the weather doesn’t undergo sudden changes.
If the water temperature falls below 68 degrees Fahrenheit, mollies will become prone to diseases, their breeding will be inhibited, and their growth will be hindered.
What is the Ideal Water Temperature Range for Mollies?
As a tropical fish species, Mollies generally prefer a warmer aquarium environment where the water temperature ranges between 71 and 85 degrees Fahrenheit.
You can achieve this temperature range with or without the use of a heater depending on your region as we mentioned earlier. We do recommend installing a heater to maintain a steady temperature.
What’s more crucial than the water temperature falling within the ideal range is that it doesn’t fluctuate a lot. This is to protect the Mollies from being forced to readapt repeatedly, putting the fish under excessive stress that can result in health issues.
What will Happen if the Water Temperature Gets Too Low?
While Mollies can survive in cold water, bad things can happen if the water temperature becomes too low. Keep the following in mind if you live somewhere with a cool climate and you’re thinking about keeping your fish outside (for example, a pond).
In too cool water, mollies will become prone to health problems as they fail to regulate their body temperature (being a cold-blooded animal and all). This compromises their immunity and leaves them an easy target to diseases such as the parasitic one “ich”.
The growth of your Mollies will also come to a slow end as the life drains out of their bodies until they die. That won’t take long because of the amount of stress the fish will experience in such conditions.
Not to mention, reproduction among your Mollies won’t be possible because of the stress of the cold and being busy trying to not die.
What will Happen if the Water Temperature Gets Too High?
It’s not just cold water that can affect Mollies, but too much warmth can also be harmful. If the water temperature exceeds 88 degrees Fahrenheit, the following risks will arise:
- Lower oxygen levels in the water, possibly leading to suffocation.
- Increased ammonia levels due to the elimination of good bacteria in the tank.
- As with lower temperatures, too hot water will put the fish under a lot of stress which will only make things worse.
Wrap Up
So, can mollies live in cold water tanks? The answer is yes.
Mollies can endure living in a tank where the water temperature is low because they’re hardy fish. They have even been known to live in outoor ponds.. However, since this isn’t their ideal condition, mollies won’t thrive in cold water, they’ll only survive.
Mollies prefer warmer water temperatures ranging between 71 and 85 degrees Fahrenheit. But if it drops under 68 degrees Fahrenheit, mollies will become prone to diseases, stunted growth, and hindered breeding.