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How To Improve Your Molly Fry Survival Rate!

As the number of people actively breeding mollies continues to increase, we have noticed more and more people asking various questions about improving their molly fry survival rate as much as possible.

This is partly just to improve the pairing yields but with the rare pattern mollies having a very high price tag right now, every molly fry that survives increases the chances of you getting a molly with rare colors or patterns that is worth considerably more than a regular molly.

Thankfully, there are some very easy things that you are able to implement to drastically improve the survival rate of your molly fry that are very beginner-friendly to do.

In addition to that, implementing some simple practices such as removing the mother molly from a breeding tank once she gives birth to her live babies will drastically increase the survival rate of your molly fry due to mollies eating their own babies given the chance.

This is why a number of people who are seriously trying to breed their mollies, especially if they are implementing selective breeding for rarer mollies will get dedicated breeding tanks.

Even a cheap small tank can be enough to put your pregnant molly in until she releases her fry then to use as a nursery feeding the fry vinegar eels or micro worms until they are large enough to be put into your main aquarium.

What Is The Normal Molly Fry Survival Rate?

It is difficult to work out the average survival rate of mollies as there are so many variables involved but a rough estimate for wild mollies is less than one percent of fry will survive.

For pet mollies the average is probably closer to five percent but can be increased to around fifty percent if you implement some relatively simply fish breeding techniques.

Doing something as simple as putting the pregnant molly into a birthing tank to spawn her fry and then putting her back into your main tank can be enough to pump the survival rate of your fry up to over forty percent in some situations.

You are then able to optimize the diet of the fry and have active cultures or supplies of vinegar eels or micro worms to further increase the survival rate of your mollies and push it over the fifty percent mark.

Those two simple steps are by far the best actions that you are able to do to help as many of your molly fry survive but they are generally not realistic options for the average fish keeper but then on the flipside of that, the average fish keeper tends not to really care about increasing the survival rates of their fry.

If you are looking to switch over to being a molly breeder with a goal of selling any rare fish that you are able to produce then we would highly recommend you at least invest in a dedicated, cheap, nursery tank.

“male alpha molly” by h080 is licensed under CC BY-SA 2.0. To view a copy of this license, visit

How To Improve Your Molly Fry Survival Rate!

The easiest way to improve the survival rate of your molly fry is to remove the potential predators from their tank that will see molly fry as food and this includes their parents.

This can be as simple as adding more live plants and fish hideouts to the tank to setting up a dedicated nursery tank.

The second most common reason that your molly fry survival rates will be so low is poor nutrition as the majority of normal aquariums simply don’t have the required food sources for fish fry.

This is where vinegar eels come in as they are cheap and ideal for young fish fry to feed on before they grow large enough to be moved onto micro worms.

Water parameters and water flow rate also pose a threat to molly fry when they are very young as they are more sensitive to pressure, temperature, and toxicity levels.

After the fry are a week old this does tend to drop off as the fry become used to their tanks water parameters but it is a quick and easy thing to monitor if you are intentionally trying to breed your molly fry.

Use A Nursary Tank Or A Breeding Box!

As we touched on above, using a dedicated, cheap, nursery tank is probably the single best investment you are able to make in improving the survival rates of your molly fry.

Even adding a breeding box for around $10 should be able to help pump up the survival rates of your molly fry though.

This ensures that your molly fry has plenty of shelter away from potential predators that do include their own parents as livebearer fish will give birth to fry and then turn around and try to eat their own babies a few minutes later.

This is one of the drawbacks of using a breeding tank and keeping the parents of any fish in the tank and not removing them in time.

Even just the mother of your molly fry is able to rapidly eat all of her fry within about a week if she is left in the tank and there is minimal cover available for the fry.

There are a huge number of different ways that you are able to implement various types of breeding tank, nursery tank, and breeding box setups though.

This allows you to come up with a setup that should be able to meet your needs and budget yet drastically improve the survival rates of your molly fry without having to do anything else.

What Should You Feed Molly Fry To Improve Their Survival Rate?

Another easy win to help improve the survival rates of your molly fry is to simply have a plan to meet their nutritional needs as soon as the mother spawns her fry.

This will often catch people out and leave them scrambling to find suitable food sources for their molly fry when they require nutrition the most!

Our general recommendation and diet progression is to use vinegar eels as the primary food source for your newborn molly fry for anywhere from two days to five days and then try to move them onto micro worms for another week before finally adding brine shrimp.

It tends to work out much cheaper if you just purchase a brine shrimp hatchery kit and add eggs as required to keep a constant supply of baby brine shrimp for your molly fry.

Although there are a number of food options available after baby brine shrimp, we usually just recommend you stick with baby brine shrimp until the molly fry can be moved onto flake food.

There really are a number of different ways that you are able to feed your molly fry though with most of them being fine but the main thing you have to do is have some sort of plan to stick to with having some vinegar eels available right away usually being recommended due to their tiny size making them ideal for fry.


That brings our article going over how you are able to improve your molly fry survival rate to an end. We hope that we have been able to help you better understand the various ways that you are able to increase your the survival rate of your molly fry and get your survival rate to over fifty percent. It really does tend to be easy with a little planning and often costs much less than the majority of people initially think.