I can see little baby fish in my tank. They look just like all the fry pictures I've seen on the net. I did not mean to breed. (I've got a calico ryukin and a black moor--both of breeding size.) I would like the babies to live and grow--but with minimal effort. What's the absolute least I should do? (By the way, I've got a big apple snail and two of her children in the 20-gallon tank too with lots of anacharis.)

Well, accidental breedings are just as welcome! My guess would be that the anacharis and the hiding places they provide is the reason that the fry was able to survive without the parents eating them. The least effort you have is getting a tank divider and putting the parents on one side, the fry on the other, for now anyway. Of course, the fry is gonna grow, and with size they need a bigger tank space themselves. Otherwise you risk them being stunted in growth.
Somethine else cheap are the rubbermaid container sold at nnnnnn and other places. They fit a hang-on filter on them perfectly, and you provide plenty of space for the fry to grow without the risk of the parents eating them....
Enjoy the fish babies!

you couls get a "breeder net" from your lfs. they are very cheap and dont take up as much space as a divider. water will be able to flow freely through it as well.