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 is a Molly Fish?

The prolific livebearer can be found in saltwater, freshwater, and brackish habitats 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 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. If you have naturally hard tap water, your mollies may not have any problems, but if you have soft tap water that lacks minerals, they may develop diseases like ich (white spot disease), fungus, and livebearer disease. For people with soft tap water, we suggest adding Wonder Shells or Seachem Equilibrium to increase the amount of calcium, magnesium, and 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). 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 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 and male sailfin mollies

Do mollies nip the fins of other fish? Generally speaking, mollies are peaceful fish. However, they are very active and often nibble on things to see if they are edible. Slow-moving, long finned fish might not make the best tank mates.

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. Avoid putting larger mollies with smaller animals like cherry shrimp because they will most likely get eaten.

What does Molly Fish Eat?

Mollies are not picky eaters and are first in line to gobble up anything you drop in the aquarium. Mollies are omnivores and need a variety of protein and vegetable options. 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. 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 for a rounder body shape. You should check their waste to determine if they are being overfed.

How to Breed Mollies

Hobbyists joke that all you need to do is add water and livebearers will multiply. 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. 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 moles may have drab colors when they are born, but will soon develop vivid colors like 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. Depending on the water temperature and amount of food eaten, it may take four to nine months for a baby molly to reach juvenile size and be ready for rehoming. Learn more about how to sell your extra mollies in our article on How to Breed Aquarium Fish for Profit.