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 Fish?

The prolific livebearer can be found in saltwater, freshwater, and brackish habitats from the Southern United States to Columbia. Their bodies are more compact than platies, and they can grow up to 4-5inches (10-13cm) 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). Hybrids are selectively bred for black, dalmatian or balloon-colored mollies.

Mollies are very popular because they come in a multitude 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. Therefore, the fish farms often raise them in brackish water that has both high pH and GH (or 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. Although your mollies will not be affected if you have hard water, they could develop problems if you have water that isn’t mineral-rich. 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). They also prefer pH, KH and GH higher because of their tolerance for salt.

How many mollyfish should I get? Mollies are known for their love of breeding, so it is a good idea to have at least two to three females per male. This ratio gives the girls a break from the constant attention of the boys. The gonopodium is a stick-shaped male anal fin, while the gonopodium of a female anal fin is fan-shaped.

Female (left) and male (right) sailfin mollies

Do mollies nip the fins of other fish? Generally speaking, mollies are peaceful fish. They are active, however, and will often nibble at food to determine if it is edible. Therefore, slow-moving, long-finned fish may not be the best tank mates for them.

What kind of fish can you mix with mollies? These fish will do well with other community-friendly fish that are close enough to each other in size and environmental conditions. Ours have been kept with cory catfish and cory catfish as well as tetras (tetras), loaches, barbs and other livebearers. Do not place larger mollies alongside smaller animals, such as cherry shrimp. They will be most likely to get eaten.

What are Molly Fish Eaten?

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. If the mollies often have long strings of normal-colored poop hanging from their bodies, you may be overfeeding them and need to cut back their portion size. If they seem to be outcompeting other fish, you might consider feeding them fish foods that are scattered throughout the tank. This will give them a chance for other animals to eat.

Balloon Mollies are bred for a rounder body shape. You should check their waste to determine if they are being overfed.

How to Breed Mollies

Hobbyists joke that you only need to add water to make your livebearers multiply. Make sure to have at least one male fish and one female. Then wait between 30-60 days for your baby fish to arrive. While a new female might only give birth to a few fry, a veteran mother can have 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 might be born with drab colors initially, but they will quickly acquire the vibrant 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.