If your fry are going to be live born, make sure you have the nursery tank ready before the mother gives birth.
You can also make your own filter modification by stretching a small strip of nylon over the filter and securing it with a rubber band. It is imperative to make sure your filter is fry-safe. If it is not, it has the potential to suck up the fry.
Look for a mixture of broad-leafed plants such as Java ferns as well as grasses. Float some of the plants so that the newborns have an area near the surface to hide immediately after being born.
Estimate needing around 5 watts from your heater for every gallon of water in your aquarium. Talk with a specialist at your local aquarium store to get the right heater for your setup. Use an aquarium thermometer to monitor the temperature of your tank and ensure it is consistent.
Rinse the mesh in warm, fresh water before hanging it in order to ensure it is as clean as possible for the fry. Keep in mind that fry will quickly outgrow the mesh and may still need a larger tank separate from other adult fish before they are ready to be introduced into your larger aquarium.
Adults, especially males, may feed on newborn fry, so it is imperative to move the mother into the nursery tank before the fry are born.
Try to get your fry home as fast as possible. You want to minimize the amount of stress on your fry, so avoid taking long routes home or stopping while you still have the fry in transit.
Introducing your fry into your tank without acclimating them may shock their system and lead to some of the fry dying off.
If you are using a breeding trap, you may want to hold the trap right at the surface of the water and gently allow the water to flow out of the plastic bag in order to prevent any fry from escaping into the larger aquarium.
Observe the mother to make sure she is not acting aggressively toward the newly hatched fry, if they are in the same tank. If so, move the mother back into your regular aquarium.
Regular flake food may be too large for the fry to handle. Use a coffee grinder or a mortar and pestle to grind up your regular fish food into a powder that is more manageable for the fry. Keep to a regular feeding schedule. Feed your fry small amounts of food, about a pinch at a time, several times a day. To make it easy, feed the fry immediately before or after you eat. Clean any uneaten food from the tank. Use a net or a skimmer to get powdered food off of the surface of the water.
Look to change about twenty percent of the tank’s water every day. That means that if you have a 10 gallon aquarium, you want to take two gallons a day out and replace them with two gallons of water from your regular aquarium.
Do not move the molly fry until you are sure they are ready to handle your larger tank. Moving the fry prematurely may cause tension between the fry and your other fish.
Clean or rinse the trap before setting it in your aquarium. This ensure the safety and health of your current fish, as well as the fry.
Do not overcrowd the breeding trap. Make sure the fry have enough room to swim around comfortably while you transfer them. Do a few at a time so that you do not crowd the trap.
Observe the fry for a few minutes after letting them out of the trap. Make sure that the fry aren’t being antagonized or harmed by any of your other fish.
If an individual fry seems to be struggling in your aquarium, you may consider moving it back to the nursery tank or into the breeding trap for a few days before retrying to acclimate it.
