I have 4 Mollie fry and I have had them for about 3 months. They aren't growing and some of them have a brown line on their fins. They are in a 20 gallon tank with 2 other Mollies, 2 plecos (I'm getting another tank for the plecos in about a month) and an angel fish. I do at least a 20% water change every other day and the filter is clean. I have an air bubbler in the tank for extra oxygen and the temperature is usually around 70 to 79° F (21 to 26° C).

Why are my Mollie fry not growing?

  • 2
    you do not mention what type of food you give to the babies,they are too small to eat normal flake food so you have to give them some type of fry food. Dec 31, 2017 at 20:52
  • or pulverize flakes to be almost dust with your hand or a mortar. This also decreases the change that the larger Mollys will take away the food from the fry because it's distributed more into the water. Jan 1, 2018 at 16:03

1 Answer 1


I would imagine they aren't eating any food since your other fish are eating it first OR the food flakes are too big. I'd suggest getting a mesh breeder that hangs on the side of your tank and really crush the flakes in your hand until it's practically dust to feed them. Or just really ensure they are getting some of the food you're feeding everyone else.

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