Care Guide for Mollies: Feeding, Breeding and Tank Mates


Care Guide for Mollies – Feeding and Breeding of Mollies, as well as Tank Mates

One of the most popular aquarium fish found at pet stores are mollies because of their wide selection of colors, energetic behavior, and ease of breeding. If you are looking for a livebearer (or fish that bears live young) that is bigger than a platy but smaller than a swordfish, then mollies strike a happy medium. While molly fish are fairly easy to care for, beginners sometimes struggle with them, so find out the secret to caring for mollies and successfully breeding them in your home.

What are Molly Fishes?

This prolific livebearer is found in freshwater, brackish, and saltwater habitats ranging from the Southern United States to Columbia. They have a more streamlined body compared to platies and can reach up to 4-5 inches (10-13 cm) in length. They are surprisingly good at cleaning aquariums, constantly scavenging for leftovers and pulling off hair algae with their flat mouths.

What are the different types of mollies? The most common species in the aquarium trade include Poecilia sphenops (short-fin molly) and Poecilia latipinna (sailfin molly). The hybrids can be selectively bred to produce black, dalmatian and balloon mollies, as well as gold dust, platinum, creamsicle and other varieties.

Mollies are very well-liked because they come with a variety of colors, patterns and shapes.

Does mollie need salt in water? Some fancy mollies are raised in countries where salt water costs less than fresh water. Fish farms raise fish in brackish water with high pH and high GH (or hardness) to keep them healthy. When these brackish-bred mollies are transported to wholesalers, fish stores, and home aquariums that use fully freshwater setups, the change in water parameters can cause their kidneys to shut down. Your mollies might not experience any problems if they have hard tap water. However, mollies who have soft tap water may be susceptible to diseases such as ich, livebearer disease, and white spot disease. We recommend adding Wonder Shells and Seachem Equilibrium to soft tap water users. This will increase the levels of calcium, magnesium, as well as other beneficial minerals, in the fish tank.

How to Set Up an Aquarium for Mollies

Depending on the type of molly fish, we recommend getting an aquarium that holds at least 20 gallons of water, but a 29- to 55-gallon tank is more suitable for larger species. For most homes, they require an aquarium heater to raise the temperature to 75-80degF (24-27degC). They also prefer pH, KH and GH higher because of their tolerance for salt.

How much molly fish should you have? Mollies, like many livebearers love to breed so we recommend at least two or three females for each male. This allows the girls to have a break from their constant attention. (A male can be identified by his stick-shaped anal fin called a gonopodium, whereas a female has a fan-shaped anal fin.)

Female and male sailfin mollies

Can mollies nibble on other fish’s fins? Mollies are generally peaceful fish. Mollies are active fish and can often be seen nibbling on food items to check if they’re edible. They may not like slow-moving, long-finned fish as mates.

What fish can you put with mollies? They do well with other community fish that live in similar environmental conditions and are close in size to avoid predation. We have had great success keeping them with cory cats, danios and tetras as well as barbs, loaches and other livebearers. You should not put larger mollies together with smaller animals such as cherry shrimp, because they are more likely to be eaten.

What do Molly Fish Eat?

Mollies are not picky eaters and are first in line to gobble up anything you drop in the aquarium. They are omnivores so provide them with a healthy mix of vegetables and proteins in the form of Repashy Soilent Green gel foods and high-quality pellets, flakes and pellets. You may need to reduce the amount of food you give your mollies if they have a lot of normal-colored poop hanging off their bodies. You might also consider giving fish food that is scattered all over the tank to other animals, in case they outcompete other fish.

Balloon mollies are bred to have a rounder shape, so check the amount of waste they produce to see if you are overfeeding them.

How to Breed Mollies

Hobbyists joke about how all it takes to multiply livebearers is water. Just make sure you have at least one male and one female, and then wait 30 to 60 days for the baby fish to arrive. A new female might only give rise to a few fry while a veteran mom can raise more than 50 offspring. The adult mollies will predate on their own young, so increase their survival rate by providing lots of dense aquarium plants like water sprite, water wisteria, and Pogostemon stellatus ‘octopus’ as hiding spots.

Baby mollies may be born with relatively drab colors at first, but they will quickly develop the vivid hues of their parents.

Livebearer fry are much larger than the tiny eggs that hatch. They can eat crushed flakes and small fish food, Repashy gel (in powder form), as well as live baby brine shrimp. A baby molly can reach adult size in four to nine months depending on the water temperature and food consumed. Learn more about how to sell your extra mollies in our article on How to Breed Aquarium Fish for Profit.