Care Guide for Mollies: Feeding, Breeding and Tank Mates


Care Guide for Mollies – Feeding, Breeding, and 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 Fish?

This prolific livebearer is found in freshwater, brackish, and saltwater habitats ranging from the Southern United States to Columbia. They are shorter than platies and can grow to about 4-5 inches (10-13cm). 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 popular because they come in a multitude of colors, patterns, and shapes.

Do mollies need salt in their water? Many fancy mollies are bred in overseas locations where salt water is cheaper than fresh drinking water. The fish farms often raise them with brackish water, which has high pH and GH (or high water hardness). 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. To increase the beneficial minerals of your fish tank, Wonder Shells or Seachem Equrium can be added to people who have soft tap water.

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). Given their high tolerance for salt, they also prefer higher pH, KH, and GH.

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 ratio allows the girls to get a break from the boys’ 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.)

Male (left) and Male (right) sailfin moles

Are mollies known to nip other fish’s fins In general, mollies can be 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 are you able to put with mollies. They can be kept with other community fish who live in the same environment and are similar in size, in order to avoid predation. We’ve had success keeping ours with cory catfish, danios, tetras, loaches, barbs, 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. Because they are omnivores, provide a good mix of proteins and vegetables in the form of high-quality flakes, pellets, frozen foods, and Repashy Soilent Green gel food. If your mollies have strings of normal-colored poop hanging down from their bodies, it is possible that they are being overfed. You might need to reduce their portions. 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 may only give birth to a handful of fry, but a veteran mom can produce more than 50 offspring at a time. 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.

Compared to the tiny fry that hatch from eggs, livebearer fry start off much bigger and able to eat crushed flakes, Easy Fry and Small Fish Food, Repashy gel food (in powder form), and 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.