Coldwater mollies

Question
I have recently bought some coldwater mollies, one male one female, a few days after buying the female she gave birth to 30 fry. The babies are a few weeks old now and have hardly grown, they were in a small tank for a week then placed in about 15 gallons of water for the last 2 weeks. they have hardly grown. I have just bought a 35 gallon tank and am going to move them into in about a week. Is it ok to heat the water once i put them in as i know mollies are generally tropical fish thought he ones i have have been acclimatised to coldwater. Will it help them grow faster? Also can i put my adults in a heated aquarium and how big should the fry be before i put the adults with them. The heater i have isnt adjustable and i believe it is automatically set to heat the water to 26 degrees celcius (79 Fahrenheit i think)  is this ok?

Answer
Hi,
Mollies are not coldwater fish, so will not take kindly to being in coldwater environment. They will be stunted because of the low temperatures and there is a higher risk of the young becoming deformed. They like water between 26 and 28 Degrees Celsius. So yes, gradually warming the water will speed of their growth.
You can keep the fry with the adults when the fry are around 2cm long; basically when they are too big to fit in the adult's mouths.
Be careful not to suddenly raise the temperature, as any sudden extremes of temperature can easily kill them.

Just one last note, feed the fry with crushed flake food and baby brine shrimp.

Best of luck,
Kathryn