Help me! What does baby fry eat because I don't know what to feed them. Also can I put the fry into a place there's a heater but no filter?

So.. I was doing a water change for my betta fish and I noticed these small little things just moving around the water. I got the water from my goldfish tank because the betta fish water was so bad that I needed to get it from my goldfish tank. When I transferred the goldfish water to my betta tank, I saw 4 baby fry in my betta tank. My betta tank doesn't have a filter, but it doesn't have a heater, and now the fry is still in there! I don't know what the fry eat, I don't know if it lives in a filter area, I just don't know anything! HELLP
Answers

Quetzel: Here's some help https

Here's some help https://pets.thenest.com/baby-bettas-eat-4783.html

noselessman

The fry will be very sensative. It is important that they have the best possible care. If you do not have a filter in an aquarium, then the aquarium will contain toxic ammonia. Which Is going to kill the betta/reduce its life span/poisan it intill it dies. Will the fry survive in it? I dont even know what kind of fish they are!, If they are gold fish, they should not be at the same 78-82 degree tempurature as the betta. Plus bettas are carnivores and are likely to eat the fry. Plus, you said the betta tank was Filthy! Why would you put dirty goldfish water into another tank? USE TAP WATER. I would suggest - catch the fry, put them in breeder net in the goldfish tank. Get some fish baby food at the petstore, feed 2-3 times a day the tiniest amount. Use a gravel vacuum to change 25-35% of the water in the betta tank, replace it with TAP WATER, that is a similare tempurature as rthe water already in the tank. If it is as dirty as you said, Clean it again every day 3 more times, and then back to once a week. Add Seachums prime and seachum paraguard, 2 drops per gallon, to all new water, and but a filter ASAP!