Raising up to three molly fish in a 10-gallon tank is possible. However, it’s not ideal because the fish won’t be able to move as freely as they need to. So it’s better to use a larger tank.
Mollies lead their best lives when living in schools of many fish and when having the ability to swim around freely and calmly as they do in nature. In this article, we’ll explain the best conditions to raise mollies in a 10-gallon tank and why we don’t think it’s a good idea.
How Many Mollies Can You Keep In a 10 Gallon Tank?
Molly fish come in various types, each with its size. Therefore, the number of mollies that can be kept in a tank depends on two things: the fish size and the tank size.
The average size of a full-grown molly fish is about 4 inches for females and 3 inches for males. With this information in mind, you can house either three mollies or two mollies in a 10-gallon tank, depending on their gender.
Rule of Thumb For Number of Fish Per Tank Size
There’s a commonly used rule to decide the number of fish that can be kept in a tank depending on its size. The rule is “one inch of fish per gallon.”
While this rule can be used to estimate and have a general idea of the number of fish you can house in your tank, it’s not 100% accurate. The rule doesn’t take into consideration that different fish of the same type can grow into various sizes. It also doesn’t account for decorative objects in the tank, like rocks and plants.
How Many Black Mollies Can You Keep In a 10 Gallon Tank?
Blackfin mollies are among the most common types of mollies. A fully-grown black molly could reach a size between three to six inches, with females usually being a couple of inches bigger than males.
Considering that the average size of a black molly is three inches, and using the “one inch of fish per gallon” rule, you can house three fish in a 10-gallon tank. However, if your black molly happens to grow into one of the bigger ones and reaches the six-inch size, then one fish per a 10-gallon tank is more than enough.
How Many Dalmatian Mollies Can You Keep In a 10 Gallon Tank?
When in captivity, dalmatian mollies can reach a size of around 4.75 inches long. Using the rule, you could house a maximum of two dalmatian mollies in a 10-gallon tank.
However, dalmatian mollies are some of the most energetic and sociable breeds. They prefer to live in schools and require enough space to swim, so they can flourish and live in well-being. So while keeping two dalmatian mollies in a 10-gallon tank is possible, it’s not recommended.
How Many Lyretail Mollies Can You Keep In a 10 Gallon Tank?
Lyretail mollies can grow into different sizes depending on their gender. Females can grow up to five inches long, while males are considerably shorter, reaching only three inches.
Using the “one inch of fish per gallon” rule, a 10-gallon tank can house either two female or three male lyretail mollies. However, it’s always a good idea to keep mollies of different genders together instead of the same genders.
In a 10-gallon tank, the best-case scenario is to keep one female and one male lyretail mollies together so they can co-exist peacefully and have enough room to swim freely.
How Many Sailfin Mollies Can You Keep In a 10 Gallon Tank?
Sailfin mollies usually grow to five inches and rarely exceed that length. While according to the rule, you can house two sailfin mollies in a 10-gallon tank, this may be pushing it too far and is not recommended.
How Many Gold Doubloon Mollies Can You Keep In a 10 Gallon Tank?
Gold Doublon mollies can grow to reach five inches in length. Again, using the rule, you can house two Gold Doubloon mollies in a 10-gallon tank, but we recommend you keep it to only one fish instead or get a bigger tank.
Male To Female Mollies Ratio In a 10 Gallon Tank
The ideal environment for developing a live-bearing colony of mollies is two females and one male. Male mollies are very persistent, and this arrangement helps spread their attention between the two females. This protects the females from getting stressed and suffering from health issues when being over-harassed by males.
The tank should also contain bushy floating plants, as they offer a hiding space for females to use when needing to escape the male’s attention.
Reasons To Avoid Keeping Mollies a 10-Gallon Tank
While according to the “one inch of fish per gallon” rule, it’s possible to raise mollies in a 10-gallon tank, it’s not the best of ideas. Here are some reasons why you shouldn’t raise mollies in a 10-gallon tank and why you should consider a bigger one:
Mollies Get Stressed
Mollies are active and sociable fish that prefers to live in schools and have enough room to swim around freely. Having a 10-gallon tank will allow you to house a maximum of three mollies and will not provide them with the space they need to flourish. This will end up causing your mollies to be stressed.
Stressed mollies will suffer from many well-being and behavioral issues, which could lead to them leading an unhealthy life and may even shorten their lives considerably.
Mollies Get Lonely
Mollies are schooling fish, and keeping them in such a small tank like a 10-gallon can only allow for housing three mollies, depriving them of their natural living habits.
It’s suggested that the minimum number of mollies kept together should be four, while six is ideal for them to form their unique schooling habits. Housing only two or three mollies will end up causing them loneliness, which leads to stress and anxiety.
Have Another Tank Size You’re Looking for?
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Bottom Line
While a 10-gallon tank could house two or three mollies depending on their breed, it’s not the ideal option and could cause the fish to suffer from many issues.
Mollies prefer spacious areas to swim around due to their energetic nature. They also tend to thrive when living in schools of six. Providing mollies with these conditions is essential for allowing them to lead healthy lives and reduce the risk of them suffering from health issues.